Skip to main content

Full text of "73 Magazine (April 1972)"

See other formats


WORLD REPEATER LIST 



ALL 50 STATES AND 
8 Foreign Countries. 







« 









EQUIPMENT REVIEWS 

Drake TR-22 
Ross & White BND 
lComcraftCTR-144 






73 EUROPEAN TOUR 
INCLUDES MOSCOW 

FCC INSIDE SCOOP 

BIG MOVE TO SAVE 220 MH 

FM SYMPOSIUM A SUCCESS 

NOVICE NEWS 



i 



50 MHz NEWS 
DX NEWS 



J 

















■t 



^^F? W 




73 



GOES 






3 week ham oriented tour of Copenhagen, Ber- 
lin, Moscow, and Amsterdam. 

Here's your chance of a lifetime to realize the amateur radio open 
ator's dream of touring the great European capitals, yet not missing out 
on valuable hamming time. Think of it — sending CQ's from 
Rembrandt's bedroom — contacting rare DX from the top of Tivoli's 
highest roller coaster — bleeping 94 direct from the middle of Red 
Square! Nirvana. 

Seriously, this could be the most thrilling trip you'll make. You will 
be with other hams, people who are interested in the same things you 
like. You can exchange eyeball QSL's with your DX friends. If our 
plans go through you will be able to operate from a private or club sta- 
tion in each city. And you can argue with a captive Wayne Green for 
three whole weeks. What could possibly be more sou! satisfying? 

Well, maybe all the traditional joys of Europe, There are gourmet res- 
taurants, quaint hotels, elegant nightclubs, famous art museums, unu- 
sual shopping bargains, Since this is not an "organized" tour, you can 
discover all these things in your own way and at your own pace* Spark 
a romance beside the Amsterdam canal, carouse all night rn Copen- 
hagen, climb the Berlin Wall — we won't bother you. But we'll be there 
to help if you need it. 



The Schedule: 
Monday, September 4 
Sunday, September 10 
Friday, September 15 
Wednesday, September 20 
Monday, September 25 



New York City to Copenhagen 
Copenhagen to Berlin 
Berlin to Moscow 
Moscow to Amsterdam 
Amsterdam to New York 



* Be sure to watch * 
73 each month for 
new exciting information 



Each of these cities holds an active ham group. Plans are to have a 
hamfest or banquet at each stop, so that you can really tune in on the 
European ham situation* 

Plan now to be free in September, You will never have a better 
chance to go on a trip that fulfills your wishes so exactly. 

YES! I am interested in going on this fabulous tour. 

□ sign me on. I enclose $200. deposit (returnable) 



Qsend me more information 

Name 



Call 



ssssussssssssssssssss 



ONLY. . . 



Street 



City 



State 



Zip 



$700.00 for single, $1300.00 for couple traveling together in- 
cludes - air and ground transportation, lodging, breakfasts, 
hamfests and banquets. 




magazine 

for radio amateurs 



=139 APRIL 1972 



FEATURES 

2 Amateur Radio Newspage 

5 Hot Gear 

6 With the FCC 
8 Novice Column 

10 Never Say Die W2NSD/1 

11 New Products 

13 Social Events & Contests 

14 DX Footnotes 

15 Letters 

16 Caveat Emptor 
28 Propagation 

28 Advertiser Index 



STAFF 

Editor-Publisher 
Wayne Green W2NSD/1 

Assistant Editor 

EricFatkof K1NUN 
Technical Editor 

Ed Webb W4FQM/1 
Assistant Publisher 

Yvette Grimes WA8ULU/1 
Associate Editors 

Jim Kyle K5JKX 

William Turner WA0ABI 
WTW Editor 

Dave Mann K2AGZ 
Advertising Manager 

Lin Green 
Art Director 

Roger Block 
Graphics 

Philip Price 

Donna A, Lavoie 
Composition 

Ruthmary Davis 
Subscriptions 

Dorothy Gibson 
Circulation 

Barbara Block 
Comptroller 

Georgiana Sage 
Publications 

Biff Mahoney 
Traffic 

Taylor Sage 
Propagation 

John Nelson 
Drafting 

Wayne Peeler K4MVW 

R. ICWildman W6MOG 



CONTENTS 

17 200 Watt 2m Amplifier 

Now you can be unpopular in six counties. 
25 Using the Drake TR-22 . . . . - t . 

Does more than DU2. 
27 An Auto-Bandwidth Selector Unit 

Using two ICs. 
31 'Break" . . 

A typical day on 2m FM_ 

36 AFSK-MCW-CPO IC 

Prizes if you can translate that. 

37 Using the LM373 . **,>,*■„ 

l-f amplifier IC projects. 
45 Repeater Site Alarm , . . * 

Hear your gear being stolen or vandalized. 
49 T44 Base Station Conversion 

G etting on 450 MHz for $30-$50_ 
51 The HR 2 as a Base Station ■-„., 

Power supply, deviation meter, etc. 
55 FM Repeater Guide ........ P .«. . 

World's most complete list of repeaters, 
86 Electronic Symbols & Abbreviations 

Just what you've always wanted to know. 
93 73 Tests the Comcraft 

Tunable receiver shakes FMers to core. 
95 The Florida Repeater Mess 

Bad, but California leads again, 
99 Ross & White Transceiver ........ . 

With tone burst built in, yet. 
101 Ionospheric Effects of Thunderstorms . . 

Peturbations occur. 
104 FM as seen by 

If the shoe fits . . . 
107 Circuits, Circuits, Circuits . . . 

Build, build, build. 
109 Extra Class Questions and Answers ..... 

Are you ready for the $9 questions? 
117 Poor Man's FM Base Station 

Is FM for under $75 low enough? 



...W4RIZ 



W4FQM/1 



. - W2EEY 



K1NUN/1 



K9MRL 



K4DHC 



K6MVH 



K0MOC 



WB6BHI 



Staff 



Staf 



W2NSD/1 



■ ■ 



# . 



.WA4RLG 



W4FQM/1 



. WN5COZ 



. W6EIF/4 



* . . • . otdi 



. . . . .Staff 



.WA4UZM 



73 Magazine is published monthly by 73 f /nc, Peterborough, New 
Hampshire 03458. Subscription rates are $6 for one year in North 
\meria and U.S. Zip Code areas overseas, $7 per year elsewhere. 
Two years S 1 i in U.S. and $12 overseas. Three years $15, and $16 
overseas. Second class postage paid at Peterborough NH, and at 
additional mailing offices. Printed at Menasha. Wisconsin 54952 
U.S.A. Entire contents copyright 1972 by 73 Inc., Peterborough NH 
03458* Phone: 603 924 3873. Say. you might give serious thought 
to joining the 73 tour to Moscow, Berlin, Amsterdam and 
Copenhagen coming up in September, litis will be a lot of fun and 
provide you with memories to last a lifetime. The 73 staff, including 
Wayne, will be at the Dayton Hamvention and can answer any 
questions you have at that time. Dani miss Wayne on the DX 
program with slides of Jordan and King Hussein as well as on the 
FM program with hot FCC news and a plan to save 220 MHz for 
hams. 



APRIL 1972 



1 



^H 



Amateur Eabto 



APRIL MCMLXXll 



Monthly Ha 



HAMS AID 




SEARCH 



On Saturday, January 22. 1972. St. 
Louis area amateur radio operators 
were called to assist in the search for a 
young man missing from his residence 
at the St. Louis State School and 
Hospital The young man was retarded 
and partially blind. 

Initial efforts to locate the youth 
were spearheaded by volunteers from 
the local Youth Association for Re- 
tarded Citizens (YARC). After 24 
hours of search. YARC leader Tyrone 
McNary contacted county police seek- 
ing walkie-talkie radios, Sargent Joe 
Owings, Police Radio Supervisor and 
ham operator, was on duty at the time 
and immediately contacted members 
of the St. Louis Repeater Club to 
request their cooperation. One of the 
primary functions of the club is to 
provide emergency communications 
using VHF equipment owned and 
maintained by the members. 

Lionel Doak K0DCQ and Clarence 
Herron. Jr.. W0KUJ instituted call-up 
procedures, and within thirty minutes 
a dozen hams equipped with mobile 
radios and portable units headed for 
the search area. Bob Netherton 
WAQQAH established a radio 

>mmand post to coordinate the 




Arnold Krauel WA0GUD, was there 
when 73 stretched out its wings and 
claimed the land II miles east ot 
Audubon, Iowa. As you walk down 
the State Road 73's of life, watch out 
for the next place 73 strikes. Keep 
your camera ready. 



YARC search groups. Other hams 
with portable transceivers were 
assigned to specific search parties. The 
command post was transferred to Sgt. 
Owings* radio-equipped camper van 
when he arrived after duty hours, 
Darkness forced the search to be 
called off for the night. 

Sunday morning additional hams. 
YARC members. Scouts, and other 
volunteers gathered at the radio com- 
mand post to continue the search. 
Each group of eight to ten walkers 
included a radio operator. Mobile 
operators visited area churches and 
homes to inform the public, with a 
description of the youth. Many of the 
YARC volunteers had been working 
with little rest since Friday afternoon. 

Unfortunately the story did not 
have a happy ending. The body of the 
youth was found in a creek bed only 
about Va mile from the school 
grounds. However, the dedication dis- 
played by the young adult YARC 
group was an inspiration to all Their 
volunteer work with retarded citizens 
usually goes unnoticed. Their involve- 
ment and compassion was evident 
throughout the search and especially 
when the sad end was known. 

In the future, it is recommended 
that authorities faced with an emer- 
gency contact radio amateur volunteer 
communication specialists just as soon 
as the requirement for assistance is 
known. The search was into the 
second day before the St. Louis Re- 
peater Club members were contacted. 

Radio operators who participated 
include Joe Owings KOAHD, Lionel 
Doak KQDCQ, Clarence Heeron, Jr.. 
W0KUJ. Robert Netherton WA0QAH 



ECARS PREXY 

HliI Winston W2D1R on January 
15th assumed the position of Presi- 
dent of ECARS. the East Coast Ama- 
teur Radio Service. 73 Magazine ex- 
tends its hearty congratulations to Ha! 
and wishes him the best of luck in this 
position. 



Robert Wingerter K0ABA, Robert 
Familton WA0QOL. William Arm- 
strong WQNC r Randy Wachter 
WByCPG, Marianne Familton 
WA0QQM Forrest Murphy W0FEM, 
Vernon Hayes W0CYF, Neil Widener 
WA90TB, Ralph Edmonds W0KUY, 
John Landsberger K0LUX, Dennis 
Hutchins WA9RDY, Bill Reichert 
WA9HHH, Royce Brown WA^UUF. 
John Carrel WA01TL Joe Rome 
K0PJB, and Robert Silvey WB^CDF. 



JOHN K3BNS 

NEW CHIEF OF 

RULES & LEGAL 

BRANCH, FCC 

Reprinted from the X-MUrer, Perm. 
Wireless Assoc. 

John B. Johnston K3BNS, has been 
appointed Chief, Rules and Legal 
3ranch, Amateur and Citizens Band 
Division, of the Federal Communica- 
tions Commission, effective 14 Feb- 
ruary 1972. 

John will be working under Prose 
Walker W4BW, the head of the ama- 
teur and citizens branch of FCC. Ik 
replaces Bill Grenfell W4GF. who re* 
tired early in 1971. 

John was first licensed as 
KN2HHR. becoming K2HHR and 
later KSDAl before moving to Levit- 
town as K3BNS. He is a past president 
of Penn Wireless Association, past 
president of Frankford Radio Club, 
and has received numerous awards for 
his amateur radio activities. He has 
received the ARRL CD Article award, 
and has had many articles published in 
QSt. X-MITTER, CQ, and 73. He is a 
Life Member, ARKL, and ex-Assistant 
Director. John is active on all HF 
bands on CW, ETTY, and phone. He 
places high in Sweepstakes and the 
DX contesjs. 



JSeto 



Bmtx 






ws of the World 



73 MAGAZINE 



SYMPOSIUM DISCUSSESI 

FCC RULES 



Representatives o( New England 
and Eastern New York repeater 
groups discussed FCC regulations 
which they thought would be benefi- 
cial for the orderly growth of two 
meter FM. 

The first item to be brought up was 
the matter of the frequency of con l ml 
systems. Under the present regulations 
all control systems must be on 220 
MHz or above. This rule has been 
around since some time in the 30"s or 
40"s and has been a great big pain with 
little redeeming merit. Suggestions 
were made that all restrictions be 
removed regarding control frequencies 
and that the end result be de lined 
instead of the means of achieving it. 
The result is effective control of re- 
peaters in this case. 

It was proposed that control be 
permitted from mobile points- Con- 
siderable discussion brought out that 
there seemed to be no reasonable 
argument against permitting mobile 
control of repeaters. The negative 
thinkers came up with a wide array of 
improbable difficulties which might 
demand fixed control points. The 
positive thinkers countered each nega- 
tive thrust and won the vote of the 
majority. 

The same discussion got started on 
the subject of monitoring and whether 
mobile monitoring should be permit- 
led. The heretical question was raised 
as to whether monitoring was in all 
cases absolutely essential and the 
majority was again persuaded that 
under certain conditions such as 
coded access to the repeater no moni- 
toring should be required. Completely 



open repeaters should be monitored. 

The group agreed that unattended 

repeater operation be proposed to the 



The matter of control of a repeater 

brought forth a good deal of opinion 
and some heat, finally being resolved 

after much compromise with the 
recommendation that primary control 
of repeaters be on 220 MHz or above 
or by means of telephone wires or 
some other such hard wire control. 
Primary control was defined as the 
ability to turn the system on and off, 
Secondary control or emergency con- 
trol was defined as the ability to shut 
the system off or change its functions. 

The group also voted to support the 

petition that has been under considera- 
tion by the FCC lor some years now 
for extending Technician operation to 
the entire 144 148 MHz hand. 

The group voted a preference for 
40 kHz spacing between channels on 
the 220 MHz band instead of the 
rumored RACES desired standard of 
30 kHz, The wider spacing would be 
in keeping with equipment expected 
to be available soon to amateurs and 
would permit the eventual splitting of 
channels down to 20 kHz without 
undue adjacent channel interference, 
The 30 kHz standard now in use on 
146 MHz has caused great grief when 
split further to 15 kHz and this 
disaster might avoid repetition if 
RACES would go along with the 
repeater groups and agree to 40 kHz 
spacing. Equipment can be made for 
15 kHz spacing, but it would be 

tensive . , , very expensive. 



ex pi 



NEWS FLASH 



Reprinted from the February Ham 
Rag 

As we go to press. Ham Rag's nosy 
reporters have smell ed out a scandal at 
ARRL Headquarters, Seems that 
ARRL President Robt. W, Denniston 
W0DX, has been out beating ihe 
bushes in opposition to ARRL's pro- 
posal for phone band expansion, so 
the League has tired W0DX and re- 
placed him with Harry J. Dannals 
W2TUK, Director from the Hudson 
Division, as Prexy. 



CLUB 18 YEARS OLD 

RSBG RadCom The Radio Ama- 
teur Invalid and Bedfast Club, now 
has close to 400 members in 13 
countries and will celebrate its 18th 
anniversary next year. It extends a 
welcome to licensed amateurs and 
SWI/s anywhere who are handicapped 
in any way. Membership is free and 
the club's newsletter, RADIAL As sent 
monthly for a small sum to help cover 
printing and mailing costs. 

Inquiries should be addressed to 
the honorary secretary, Mrs. Frances 
Woolley G3LWY, Woodclose, Pensel- 
wood. Win can ton. Somerset, England. 



DYCOMM 
DEM A ND 



A letter from attorneys represent- 
ing Dynamic Communications de- 
mands that 73 publish a retraction as 
follows: 

The models advertised on page 
106 of the February edition were 
incorrect, that they were both 
discontinued as of January 5th, 
1972, and that new models and 
new prices were in effect from 
that day forward. 

We do try hard to see that only ads 
that are wanted are run. In the case of 
Dycomni a proof of the ad was sent 
with the following statement: "Here is 
a rough proof of your ad for the 
February issue of 73. There will be 
time for us to send further proofs and 
get your okay on any changes or 
corrections if we receive your material 
by December 10th. We cannot guaran- 
tee proofs subject to corrections on 
materia] received between December 
10th and 20th. Contract advertisers 
do not require an insertion order. As 
per contract agreement, below shown 
proof will appear in the February 
issue* Absolute ad deadline for nega- 
tives, changes and corrections is 
December 20th." 

Though this proof was sent to 
Dycomm on December 5th, no word 
of any kind was received from them 
before the issue went to press. The 
next letter received was from their 
attorneys demanding a retraction. Had 
73 received any communication what- 
ever from Dycomm, by phone, letter, 
telegram, etc., the ad would have been 
cancelled. No word was in fact re- 
ceived. 



ACTION AUCTION 

With a title like the "Action Auc- 
tion," the Montgomery ARC must be 
planning a big turnout. The auction 
will be held at the Civic Center in 
Gaithersbunz on 5unda\ May 14. 
Bring your gear from 10 to 12, and 
the auction will begin at noon. Talk-m 
on 94. 



HAVASU 

HIGH SCHOOL 

HAMS 




Left to right: Randy Strange; Gary 
Keller; Tom Clark; Howie Di Blast, 
Instructor* of WA7RTM, the Lake 
Harasu High School Amateur Radio 
Club, The club recently handled 200 
messages for students and faculty to 
all pctHs of the world. Trail it was 
passed to 25 states and many foreign 
countries. 



ADDITIONS 

TO 
TECH NIC A L 
AID 
GROUP 

(see March "72 73) 
Joseph Botwinick WA2UVD 
137-45 231 St.. Laurelton NY 
11413. Project coordinator, Joe can 
lend a hand wirh AM. antennas. 
Novice problems, converters, test 
equipment, surplus and other general 
help. 

Jim Venable K4YZI . M g Janccy 
Dr.. Marietta GA 30060, Jim is well 
qualified to lend assistance in 

VHF-UHF design of transmitters and 
receivers and antennas as well as befog 
adept with test equipment and solid 
state matters. 



By Philadelphia Hams 



TV NET FORMED ON 
439 MEGAHERTZ 



PtiutRitlmp W A SUIT 

■ 

A new rtet was started on Friday, 
January 28, 1972 by net control 
K3ZKO Ron Cohen of Philadelphia, 
What makes this net unique is that it 
is a TV net (last scan). Sponsored bv 
the Mt. Airy VHP Radio Clulx InJ 
(Pack Rats), the net meets each Fri- 
day from 7 to 10 P.M.. Philadelphia 
time. Ron (who is known as "Captain 
Video") believes that this is the first 
TV net to be formed in the hast, and 
the first of its kind anywhere in the 
U.S. The frequency is 439,25 (video 
and audio). Philadelphia hams call this 
frequency "Channel LV:!/" If you 
cannot copy K3ZKO-TV, look for 
WA3AXV-TV. whose handle is also 



Ron. K3ZKO will run test with those 
stations who wish, as well as listening 
on 14638 MH/ (2 meter FM ATV 
engineering channel I for those who 
n only receive but want to take 
part. Both Ron K3ZKO and Paul 
WA31I1T have color receivers for 
those who want to run tests while 
transmitting in color. Anyone can 
receive this net on a conventional TV 
set with a modified UHF converter 
(frequency adjusted 30 MHz at low 
end). Ron K3ZKO expects about 
twenty ATV stations from New 
Brunswick, N.J. to Westville. N.J. to 
be regular check-ins each week, and 
many more stations on 146,58 FM, 
who are monitoring only. 



QSL 
MANAGER 

OF THE MONTH 

Scott's QSL service and l)X Assn 
proud to announce l he recipients of 
the QSL Manager of the Month golden 
microphone trophy. Each month since 
September 1^70 one of the following 
managers was awarded the trophy for 
outstanding service /L2AFZ, 
\ I 3EUU, ta W7VRO. VYA3IHP. 
W3HNK, KH6GLU, 1NDXA 
(K3RLY), W3CTR WA6AHF Uyl 
Fern), WA2DWL:, W0QGI <WA0 
bum). W5QMJ (W5 huro), WBNABN, 
W2MZV (Browning DXpcd mgrl 
\\ 2GHK rDOTM), WA6MWG. K0ZFL 
iK. WB, WN 0huro». K4ZCP. 



NEWS FROM AROUND THE WORLD 






According to a newsletter of the 
Canadian Amateur Radio Federation, 
the age limit for the Amateur I v peri- 
mental Service has been dropped, the 
eleven meter band is to be turned over 
to the exclusive use of the General 
Radio Service, and the Ministry of 

Communication is considering the 
lowering of qualifications necessary 
for amateur radio operators and crea- 
tion of a new class of junior license 

restricted to operation in a UHF band 



and an output of three watts. This last 
item is particularly interesting as the 
I ARI feeling is that any matter about 
amateur radio should have the ap- 
proval of all licensed amateurs. Until 
all facls are known, however, con- 
cern ed persons should not condemn 
the Ministry. There is the possibility 
that this Restricted Amateur license 
will promote the development of 450 
MHz equipment. This will be a worth- 
while event to follow. 



NJ AMATEUR 
OF THE YEAR 

On January 2 1 si, Anthony 
Butterhof K2JOX, was presented with 
a plaque and cash award in recog- 
nition of his many years o1 service to 
the southern New Jersey area hams. 
His dedication to ham radio has been 
demonstrated many times Over the 
\ ears. 

He lias served as president and 
member of the Board of Directors of 
the Southern Counties Amateur Radio 
Association, has served onany com- 
mittees, participated in many SCARA 
activities and programs. In 1971 he 
organized several transmitter hunts, 
promoted club activities, was prime 
mover during Field Day, technical 
advisor in the installation and opera- 
tion of the club repeater, and served 
as chairman of a special committee 
ihat established WX2MAP, the special 
events station that operated in con- 
junction with the Miss America 
Pageant. Anthony acted as coordina- 
tor between the Pageant officials and 
the amateur club, lie provided for 
acquisition of material and installation 
o\ the antenna and radio equipment 
for this station, participated in the 
operation o\ rhi> station, and coordi- 
nated the QSL card efforts for l he 
event, 

Currently he is the committee 
chairman of the Kiwanis International 
special events amateur radio station, 
due to become operational this year. 
He has organized code and theory 
classes for prospective Novices at the 
local high school. And he has held 
many positions in local and county 
Civil Defense organizations. 

The award is presented each year 
by Atlantic City radio station WFPG 
to the outstanding amateur in the 
southern New Jersey section. 



METRO SNO -DO 100 



B\ Al Mnlden VE3CLE 



Reprinted from the Toronto FM So- 
ciety Bulletin 

Alter a delay of one week. Metro's 
first recorded suowmobilathon took 
place February 5, 

Presented by several Metro area 
Civitan clubs, the Sno-Do took place 
over a hundred -mile course. Similar to 
a walkathon. but run on snowmobiles, 
it offered snowmobile owners a fund 
raising, fun-type endurance test for 
their machines. It was not a contest. 
but each entrant was asked to obtain 
sponsors who paid for each mile com- 
pleted. All monies were equally divid- 
ed between the participating clubs, 
whose common objective is to fight 
mental illness and help mentally re- 
tarded citizens 



HOT GEAR 



On Feh. 3, 1972, YAESU Model 
FT- 1 1 Transceiver, S/N 1 07036, 

equipped with CW filter, was stolen 
from the automobile of WA2YSW 
while it was parked in the driveway of 
his home. Contact Frank W. 
Wi d m a n n . 3 28 Farwood Road , 
Haddon field. NU. 08033, or Officer 
La t ham , Pol i ce H ead q li a r te rs, 
Borouglr of Haddon fie Id, 242 Kings 
Highway East, Haddoufield. NJ. 
08033. 

A 2 meter FM Standard Transmit- 
ter SRC 8Q6M, Serial Number 
102703. was stolen from the ear of 
Clem Mathias W6NPV on January 25. 
1972. Contact him at 3134Coronado 
Ave.. Imperial Beach CA 9203 2, 

In Flmira, NX, Glen WU2LRR re- 
ports a Drake ML2, Model No, 20189 
100N PL, stolen. 



Lis? trom Past issues 
MU. t Model, Ser. No. 
Halli.SR46A No 446100 
Reg.. HR 2^0.04 03505 
Sonar, FM 3601, No 1003 
Colt. 75A4. No 804 
GE.Portabte, No. 1041218 
Coll . 75SE-B, No J 5640 
Coil, 21S3. No. 12000 
CoJL,516F1,No.1649 
Stmp. Mod -A, No. 35457 
SBE SB 33 No. 103906 
Heath HW22A No. 907- 1835 
Nat 1 1 HROSONo.280019 
M.iJIi SR160 No.416000 

108039 
Drake TR3 No. 3858 
Cotl., KWM2ANo 13815 

CoR, 312B4NO.59920 
COtt,30L' No. 40084 
Coll. MPL Mo. 44507 
Coll. MM1 (mob mike} 
Misco mmispkr. 

Swan SW174 No. 416-5 
Reg. HR2A No.04 05896 
HR2A, No.04-6208 
H«a!ti SB 102.No. 132 128107 



Owner 


Issue 


WA1EMU 


9/71 


WA5BNM 


11/71 


WB2ARM 


11/71 


W&MGI 


12/71 


K2AOQ 


1/72 


CoJ.St U 


1/72 


CoLSMJ. 


1/72 


CoLSt.U. 


1/72 


W2PWG 


1/72 


WA5JGU 


2/72 


W1BDX 


2/72 


WA5DQF 


2/72 


K9VVA 


2/72 


WA9EYL 


2/72 


ARRL HO 


2/72 


M. Godwin 





SgC. Hopkins 2/72 
Wilm DE Police 
W0AXT 2/72 

K4GBL 2/72 

W5FXX/5 3/72 

Wringer 3/72 

Wood bridge VA 
703,491 2257 



Point-to-point communications on 

the rally was organized and carried 
out hv the lorouto FM Society. They 
filled in the snowmobile/mobile end 
where a lack of ham mini power was 
evident. Four FM mobiles, those of 
Stan VE3AZD, Dan VE3C1Q, Barrv 
VE3FBH. and Ray VE3GSK, were 
positioned at strategic points along 
the course, and track was kept of the 
position of each snowmobile as the 
day progressed. The base station was 
supplied by Chuck VE3KQ and ably 
manned by A I VE3CLE, 

li was a good day for hams and 
siiowmobilers alike. Without ham 
help, the event could not have been as 
successful as it was other clubs are 
encouraged to lend support whenever 
and wherever reliable communications 
are needed. 



BIRD OFFERS 
REWARD 










- 



Bird Electronic Corpora rion offers 
a reward to twenty owners or users of 
a model 43 THRULINE RF Direction- 
al Wattmeter. Designed under the di- 
rection of the late microwave pioneer 
J, R Bird when the industry was in its 
infancy, production of the famous 
"4 V' has just passed the 50,000 mark. 
This portable insertion wattmeter 
measures from I to 10,000 walls from 
0.45 to 2300 MHz in discrete bunds 
determined by the plug-in element 
used . 

In celebration of the 50,000th unit, 
Bird will give away 20 standard plug- 
in elements to serial numbers taken at 
random on 10/10/72. Users seleeted 
will choose their element according to 
desired frequency range and full-scale 
power level. Mail the serial number of 
your model 43 on a card to Bin/ 
Electronic Corporation, 30303 Aurora 
Road. Cleveland (So fun). Ohio 4413*1 



THE 50 MHz BAND 

by WA0ABJ 

The December openings started off 
with a bang early in the month, giving 
rise to hopes of another period similar 
to 1 %7 but after openings the morn- 
ing and evening of the third and the 
evening of the fourth things calmed 
down. While there were multiple 
openings, they were of short duration 
and rather spotty. WA2LNZ and 
WB2BLL joined in a ragehew with 
KUR1R. WORYT and WA0ABI on the 
20th while on the following day 
VETs were heard but were too far 
down in the noise to work. 

Word has it that the 1972 meeting 
of the Midwest VHF Society will he 
held in Kansas City, but no date hjs 
been set as of this writing. Hopefully a 
date will be announced shortly SO 
those who must schedule their vaca- 
tions well in advance will be able to 
make the necessary arrangements. 
Several people from this area were 
forced to miss the l°7l meeting in 
Sioux Falls due to inability to arrange 
time off from work. A Kansas City 
l rip is in the planning stage: hope to 
see you there. 

There is good news for those in 
need of a Kentucky confirmation Ted 
WB4VLH. is newly active from Padu- 
cah with a tlegg Venus and a pair oi 
4X1 50 s. Ted joins Dave WB4YIH, 
who has been on for some time from 
Owensboro as K9DZK/4. These are 
the only Kentucky stations ever heard 
from this midwest location, W5SXJ 
was heard aeronautical mobile on 
both legs of a business trip through 
the St. Louis area. Ray seemed to be 
having a ball making contacts at the 
drop of a hat .ind at times rag chewing 
over a four state area. 

Mike W0/VS. is QRX while the 
tower is being moved to a new QTH 
and should be back on the air shortly. 

Several Heath SB-1 10\s around huve 
developed a habit of jumping from I 
to Wz kHz. in each the problem 
started abruptly and after the rig was 

vera! years old. In each case the 
problem was found to be in the 
heterodyne oscillator circuit. Should 
you have this problem, blow about S2 
and replace all the resistors and capac- 
itors in these circuits at one time. This 
may seem wasteful and you may never 
know which component was defective 
hut it is far better than removing the 
shielding and handswitch to replace 
components one at a time. 

Your assistance in supplying cur- 
rent, factual reports of activity are 
needed to keep the column interesting 
and useful I would also like to receive 
your comments as to what you would 
like to see in this space. Unless you 
speak up, you'll have to put up with 
my findings. 



HAM TUNES IN TO 
BURROWING BURGLARS 

by Henry Maule 
Reprinted from the KnoxriUe (TN) Journal 



Robert Row kinds is a prosperous 
33-year-old company director who 
maintains jji elegant apartment in 
London's West tnd. Like many a 
hard-working businessman, Rowlands 
relieves the pressure with a hobtn 
He f s a radio ham. 

At 11 o'clock one seemingly quiet 
Saturday evening not long ago, 
Rowlands turned on his high-powered 
equipment and began reaching into 
the ether for another ham, preferably 
someone far off. Perhaps he might 
even wind up chatting with none 
other than Jordan's King Hussein, 
who escapes from the woes of the 
troubled Middle East by doing a little 
radio hamming himself. 

As luck would have it, Rowlands' 
short-wave receiver was tuned in on 
27.5 megacycles. This was precisely 
the frequency of a set of walkie-talkie 
radios being employed, at that very 
moment, by an enterprising gang of 
bank robbers who had tunneled their 
way into Lloyds Bank branch on 
nearby Baker Street. 

The bank is situated only a block 
from 22 IB Baker Street, the address 
of Arthur Conan Doyle's famous fic- 
tional detective, Sherlock Holmes. 
Ironically, although their equipment 
was ultra modern, the thieves were 
employing the same technique of the 
robbers in Doyle's story. "The 
Red-Headed League," 

The non-fiction gang tunneled 15 
feet downward from a vacant store 
two doors from the bank. Then, with 
picks and shovels, they dug their way 
40 feet horizontally under a 
restaurant called "Chicken Inn 1 ' to the 

nk itself. Next, they dragged in gas 
cylinders and a thermic lance to 
attack the four- feet -thick re in fore 
concrete floor of the strongroom. A 
thermic lance is a specialized cutter 
used industrially to cut through 
concrete. 

the diggers had walkie-talkies and 
so did a lookout planted, with 
binoculars, on a nearby luxury house 
rooftop. It was on a little tete-a-tete 
between the gent on the root and the 
burrowers that Rowlands beamed in 
with his sensitive receiver. It was the 
night of this past Sept. I I . 

It took a tittle time for Rowlands 
to catch on, The first thing he heard 
was the exultant cry, in a decided I v 
Cockney accent "We've got at least 



200 grand!' The robbers had reached 
the vault* 

Like a dutiful citizen, he 
telephoned the nearby police station 
m Mary leb one Lane. His immediate 
impression of the reaction at the other 
end was that they believed him to be a 
hoaxer or a crank, but he eventually 
persuaded them to send an officer 
around to his home to hear for 
himself. 

Rowlands urged that a General Post 
Office detector van should be called in 
at once to pinpoint the source of the 
robbers' conversations. The constable 
assured him this would be done 
immediately. 

The gang's crosstalk made reference 
to drilling in the street, and there was 
also talk of a waiter in a nearby 
restaurant who kept peering through a 
window. 

Rowlands fell these were two valu- 
able clues which would help the police 
pinpoint the actual bank in which the 
raiders were so diligently at work. But 
the police did not seem to appreciate 
the importance of conversations the 
radio ham was taping. 

Furious at their lack of concern, 
Rowlands phoned Scotland Yard, told 
them what he had heard over the 
radio, and said it was quite clear a 
robbery was in progress involving a lot 
of money and valuables. 

Even though the Yard's reaction 
did indicate more interest than had 
been shown at Rowlands' local police 
station, their approach to the bank 
robbery was pedestrian in the ex- 
treme. 

Two days later, on a Monday, the 
completed robbery was discovered at 
the Baker Street Branch of Lloyds 
Bank. In the angry official inquiry 
that followed, the big question was: 
What about the Post Office detector 
van thai Rowlands had suggested? 

The Post Office people insisted that 
the robbers stopped transmitting five 
minutes after the detecting equipment 
was brought into play. 

"If we had been alerted sooner." 
said a spokesman, "we could have 
found the transmitter very quickly. 
Once in the area, we could have 
pinpointed the building in a matter of 
minutes." 

The police reported that they had 
put ,in a call for the use of the 
detector van 10 hours earlier, but had 
been told it was not possible to 



WITH 
THE 
FCC 




Following is a reprint of an article 
in the Texas VHF-FM Society NEWS 
in which a summary of Prose Walker's 
comments at SAROC appeared. In the 
relaxed atmosphere of his visit, he was 
able to comment more explicitly on 
several issues of prime interest to 
hams. This article represents a superb 
review of current F< I thinking. It 
must be remembered that Mr, Walker 
stated his ideas in places, and that 
unless indicated, these items have not 
been placed into effect. 

FCC AMATEUR CHIEF 
VISITS NORTH TEXAS 

A, Prose Walker, W4BW. Chief of 
the Amateur and Citizen's Division of 
the I XX was a guest and featured 
speaker at the January 1 0th meeting 
of the Richardson Wireless Klub. 
Throughout his visit, Mr. Walker was 
constantly bombared with questions 
about the probable outcome of the 
various rulemaking actions pending 
before the FCC, Mr, Walker was free 
and open with his answers, and lent 
considerable assurance that we are, 
indeed, represented by a ham's ham. 
He did preface his remarks with a 
caution that they be interpreted cor- 
rectly and kept in context. That con- 
text is worth explanation. 

As Chief of the Amateur and Citi- 
zen^s Division. Mr, Walker directs and 
administers the preparation of the 
report and order which is the culmina- 
tion of any rulemaking procedure. 
However tand this must be under- 
stood clearly*, the initial report and 
order prepared by his division is not 
necessarily ever issued as it was writ- 
ten. After his division^ work, the 
document must be analyzed by the 
FCC legal staff, by the Safety and 
Special Services Bureau, and finally by 



contact the tinit because it, was not on 
24 hour duty. To which the Post 
Office replied that the police had not 
indicated there was any particular 
urgency. It did nothing to reasssure 
the owners of the robbed deposit 
boxes when Scotland Yard later issued 
a statement that they and the Post 
Office were tightening their emer- 
gency links. "We have establish 
where the weaknesses were," said a 
spokesman. "We have learned lessons 
from this episode and it won't happen 
again."" 

As a certain onetime resident a\ 
Baker Street would undoubtedly have 
commented, were he around: "What 
can one expect? It's elementary, my 
dear Watson." 



the seven commissioners. There are 
many opportunities for reversals in 
this approval path, and the final re- 
port and order may he substantially 
different when issued than when 
drafted. Ml Walker's beliefs and find- 
ings, then, can be assumed to have a 
direct influence on the work done in 
his division, hut cannot be assumed to 
carry promise about the final rules. 

Mr. Walker thinks the report and 
order following docket 1 8803 (VHF 
Repeaters) might he issued before 
mid-year, It will probably be issued 
first, before the phone hand expan- 
sion, "eye bank," and 220 MHz 
hobby band subjects are finished. In 
summary, it seems that VHF repeaters 
will be dealt with kindly and almost 
completely in accord an ce with our 
Society's comments. The extensive 
linking of repeaters for non- 
emergency use might not be permitted 
beyond a total of two, or at the most, 
three machines. 

Mr. Walker believes that sub-band 
allocations as proposed by the FCC 
are not necessary beyond prescribing 
what portion of each band may be 
used for repeaters. He delivered an 
admonition that we hams coordinate 
immediately, effectively, and national- 
ly to formulate a frequency coordina- 
tion plan to obviate interference be- 
tween repeaters and stations of other 
types, and among repeaters them- 
selves. Such coordination would have 
to take into account the newly estab- 
lished amateur satellite service and 
other users of the spectrum. While not 
suggested by Mr. Walker, this subject 
seems to be of sufficient importance 
that it might well become a crusade 
within the ARRL. 

The information required on license 
applications tor repeaters may change 
to include those items directly related 
to establishing a service radius. Such 
items as height above average terrain, 
power output of the transmitter, 
transmission line loss, and horizontal 
and vertical pattern data may well be 
required on future applications. Con- 
versely, the requirement to explain in 
detail the functioning of every relay 
and other system component probab- 
ly will be eliminated, 

Access by tone may be required, if 
for no other reason than to establish 
without doubt the using operator's 
intent to key a repeater. This possible 
requirement ties directly to the sub- 
ject of unattended operation. The 
commission has apparently, regardless 
of Mr. Walker's disposition on the 
subject, not yet reached a decision 
about whether the prime responsi- 
bility for repeater operation lies with 
the trustee of the repeater or the 
licensee of the station using the re- 
peater. Carrier-operated repeaters ap- 
pear to be likely to be prohibited 



unless they are monitored and con- 
trolled full time. Tone-access repeat- 
ers, however, seem to be better eandi* 
dates for unattended operation 
although the subject is by no means 
resolved at this time. 

Logging of transmissions will pro- 
bably go, automatic identification of 
repeaters will stay (and in fact, a 
future requirement is being studied 
for fully automatic digital identifica- 
tion of all transmitters L in-band con- 
trol probably will be allowed, and a 
technical log might be required. 
Rather than list each of the points 
made by each of the comments sub- 
mitted to the commission. Mr. Walker 
indicated that we probably would be 
permitted each of the boons we 
sought - with the possible exception 
of unattended operation. He personal- 
ly believes as we do that unattended 
operation should be allowed and 
readily cites the precedent established 
by the land mobile services in support 
of his beliefs. His ability to convince 
the commission, however, will be the 
determining influence in the outcome. 
Considering Mr. Walker's knowledge, 
experience, level of concern, and un- 
derstanding of what ham radio is all 
about, coupled with his apparent deep 
interest in repeaters, it is difficult to 
be anything but optimistic at this 
point. 

Mr. Walker touched on several 

other subjects outside the area of VHF 
repeaters. Some of the more signifi- 
cant items are reported here. There 
probably will be an expansion of the 
75 and 40 meter phone bands. More 
space might be provided on 160 
meters. Ten meters might support a 
small allocation for repeaters. The 
LI A petition for reallocation of part 
of the 220 MH/_ band for citizen \ 
band operation hasnr been resolved, 
there is much pressure for its adop- 
tion, but there are serious potential 
problems in the areas of enforcement 
and the federal govern mentis priority 
in the band for radio location services. 
Because the issue is so "up in the air 
at the moment, Mr. Walker suggested 
that amateurs do nothing until or 
unless the FCC issues a notice of 
proposed rulemaking. 

The commission is concerned about 
amateurs who run more than the legal 
kilowatt, It seemed that the FCC has 
just about run out of patience with 
the problem and is prepared to legis- 
late a cure. One solution might limit 
the plate dissipation rating of vacuum 
tubes to a certain level. The best 
solution is to clean up our own ranks 
of the violators and scofftaws. The 
message was very clear. Another sub- 
ject discussed in the same unpleasant 
vein was the apparent large number ol 
frauds holding conditional and tech- 
nician licenses. In six months of 1 97 1 . 



134 licensees of various classes were 
called in for re-examination. 59 
failed to show, \7% failed the test, 
24'' passed. Suspected perjury con- 
cerning qualifications prior to renewal 
time has attracted the commission's 
attention, and steps are being taken to 
reduce the number of violations. 

The entire subject of call signs will 
shortly receive commission attention. 
Hie block of prefixes AA through AL 
have been assigned to the LLS, but 
have not been assigned in the amateur 
service as yet. Many possibilities exist, 
and the final outcome may be a long 
way off, but some examples of what 
might be done are: Extra class 
licensees might receive prefixes 
W/K/WA/WB* etc., with a one or two 
letter suffix. Advanced class might use 
part of the AA-AL block. Generals 
might set nothing but ~1 X y calls. 
Novices "2 X 3" with WN or KN 
prefixes, and repeaters the same with 
WR or KR prefixes. The idea supports 
two considerations: the most obvious 
is the benefit to the monitoring ser- 
vice in determining the class of 
licensee; and a secondary benefit is 
the incentive attached to receiving a 
prestige call in the higher class license 
erades. 

Two new grades of technician class 
licenses may be established in the 
future to replace the current techni- 
cian class They would be no-code 
licenses, but with two grades of tech- 
nical competence indicated by names 
like ^VHF general/ 1 or tfc VHF extra," 
just to cite an example. Repeater 
trustees would likely be of the higher 
grade only, Mr. Walker's discussion on 
this subject received enthusiastic sup- 
port from his audience, 

Mr. Walker's final point concerned 
the possibility of establishing more 
HI ham bands. Many countries are 
ceasing operation of their I IF fixed 
stations in favor of cables and satel- 
lites which provide much higher re- 
liability. The spectrum vacated by 
these services could be made available, 
in Mr. Walker*s opinion, if we hams 
begin to work now at a professional 
and diplomatic level. The next World 
Administrative Radio Conference in 
1977 will treat HF spectrum alloca- 
tions, and it behooves us. he thinks, to 
get busy right away within the League 
making preparations. It is a serious 
and difficult subject which encom- 
passes not only domestic but inter- 
national effort of the highest pro- 
fessional quality, but it is not im- 
possible, Mr, Walker tantalized the 
audience with visions of ham bands 
every 2 or 3 MHz throughout the 
entire Hh spectrum! 



PLEASE INCLUDE YOUR ZIP CODE 
WHEN YOU WRITE 73. 



FCC 
REPORT 

by Bill Grenfetl W4GF 

Reprinted from January IV71 

A u to -C *all R e-reprtnted front Feb- 
ruary, 1972 Ra Ra Rag, 

The ARRL response to the Com- 
mission's Docket I ^245 Notice of 
Inquiry lias been Hied and is, I think, 
quite revealing of an attitude which. 
unfortunately, does little to help the 
FCC resolve the problem. 

Briefly, this concerns Section 97.39 
of the rules which say amateur station 
licenses "will not be issued to a 
school, company, corporation, or 
other tnon-amateurl organization, nor 
for its use ..." Although it has been 
advising others of its belief that the 
ink- prohibiled amateurs from furnish- 
ing communications on behalf of 
non-amateur organizations for more 
than 14 years, the FCC's reply to a 
Lion's Club letter thai the rule applied 
to the Eye Bank Net (which is .spon- 
sored by the Lions* organization! 
caused a big Tusk and resulted in the 
writing of some rather heated and 
misleading editorials. See November 
1^71 QST. page 7 K > for the fifing, my 
June 1^71 Auto-Call report (page 5) 
and October 1 970 QST editorial « page 
9), 

While Bob Booth's work in prepar- 
ing the comments for ARRL is quite 
comprehensive and well documented. 
I believe it strays from the most 
productive direction and that some of 
the arguments presented weaken. 
rather than strengthen, the League's 
presentation. For example, the com- 
ment traces the controversial "*nor for 
its use" phrase back to the amend- 
ment Of the rule made by the FCC in 
1938 as a result of the League's 
request "to close the loophole." It 
slates that "the League most certainly 
would not have suggested the addition 
of the phrase "nor for their use" and 
"nor for its use" if there had been 
even the slightest indication that the 
phrase might even remotely be in- 
terpreted to restrict the message hand- 
ling activities upon which the League 
has been built since 1^14." League 
Secretary Warner's December 1928 
QST editorial discussing the "nor for 
its use" phrase is cited. What the 
League's comment fails to recognize 
and deal with is that the phrase has 
been interpreted to apply to com- 
munhviitms and therefore, if this is 
undesirable, the on!) way to prevent 
such an interpretation in the future is 
to change the rule It should be 
recognized that early rule language 
and interpretations cannot remain un- 
changed when the communications 



and the people involved in station 
operation and in the regulatory pro- 
cess change as time marches on! 

From my point o\ view as a former 
FCC employee of 20 years involved in 
this amateur regulatory process, 1 
think I can reflect the Commission 
staffs point of view in observing that 
the reference to the Commission "s 
"persisting in its misinterpretation of 
Section 9739" is hardly going to win 
them over. I think the views of a 
majority of the Commissioners them- 
selves is probably well represented by 
Chairman Burelfs statement to the 
Washington Chapter of the QCWA Jast 
March. I recommend that you read it. 
(QST, May 1971, page 81) 1 

The Commission and staff has given 
the amateurs and their League every 
opportunity to participate in arriving 
at an agreeable solution. I hope the 
League will see its way to forget the 
past and provide positive help to the 
Com mission, ' 

Gf 

FROM THE FILES OF THE FCC 

Finds 'em, Catches 'em, Cancels 'em! 

A U.S. District Court Jury found 
two Des Moines men guilty of vio- 
lating FCC Rules governing the use of 
CB radios. Raymond W, Huxford, 55. 
was convicted of exceeding FCC limits 
on CB radio antenna height, power 
output, length of broadcast and of 
violating FCC Rules by operating on 
unauthorized frequencies, using an un- 
authorized call sign, relaying messages 
for persons other than himself or 
family, and sending messages as a 
hobby or diversion. Mr. Huxford was 
found guilty on six counts of viola- 
tions of the Communications Act. 

James O. Edmunds. 40, was convic- 
ted of exceeding FCC limits of length 
of broadcast, operating on unauthor- 
ized frequencies, using an unauth- 
orized call sign and sending messages 
as a hobby or diversion. Mr. Fdmunds 
was found guilty on four counts of 
violation oi' the Communications Act 

U.S. District Court Judge William 
Stuart continued bond at $2500 on 
each defendant and delayed sentenc- 
ing pending pre-sentence investigation. 

Refer to 7 J, December /<>?/, for 
more details 

The General Class license of 
W9LMR is under suspension for out 

of band operation. He was monitored 
while operating on 7004.0 kHz and 
was so notified of the violation. FCC 
rules require written replies to such 
notices. LMR did not reply to the first 
nor subsequent letters and hence the 
suspension. In other action, the Extra 
Class license a\ WB4DXX is under 
suspension for the remainder of its 
term for several violations. The first 




I here is such a variety of equip* 
men I available kit form and ready 
made and homebrew too that setting 
it up for total enjoyment should be 
emphasized. Your station has to be 
efficient and comfortable too. Some 
Novices land higher class license 
prefer to install their stations m cabi- 
nets or platforms that are above the, 
operating desks, This looks well and it 
leaves the table top clear for logbooks, 
pencils, keys, and mikes. All the addi- 
tional space under the rig can be used 
for storage and also for extra room if 
your operating desk is also used for a 
work bench. This presents a neat and 
orderly appearance that is impressive 
to visitors and also convenient to 
operate if controls do not have to be 
adjusted often. 

Another arrangement is to tilt the 
front of your equipment so that it 
seems to face you as you look down 
at it. This eliminates the squinting and 
hunching down to read dials and 
meters. What's more, it looks like the 
gear is mounted on a professional 
work bench. Perhaps a short SWR 
bridge can be placed underneath to 
act as a support. This adds a nice 
touch as this otherwise empty space is 
filled with another knob or two and a 

llk ' ter ' (continued} 



was communicating without identify- 
ing his station at proper intervals, and 
for transmitting signals for a purpose 
other than communication. Official 
notices of violation were sent on two 
occasions for these and no reply was 
made. On another date, the trans- 
mitter of the licensee v\as transmitting 
in "excess of its modulation capabili- 
ties for proper technical operation, 
resulting in excessive distortion and 
frequency instability." A notice was 
sen I io WB4DXX and he replied ex- 
plaining the circumstances, A third 
violation was committed on another 
date when he willfully interfered with 
other signals. The response to this 
notice claimed the interference was 
willful but not malicious, and the 
interference was due to negligence on 
his own part. In the FCC order, the 
findings are summarized m the state- 
ment. "That the licensee's actions 
described above are contrary to the 
public interest, convenience and 
necessity standard of Sections 301 
and 3.07(9$ of the Communications 
Ae( of I $34 ..." It was ordered that 
the Extra Class license of WB4DXX be 
suspended for the remainder of the 
license term. 



8 



But is your desk set up for maxi- 
mum operating convenience? Can you 
sit at the table comfortably for several 
hours and not get tired from eye 
strain, ami muscle fatigue, writer's 
cramp > or other afflictions of the 
hum? The first arrangement described 
above looks fine and as mentioned, as 
long as you do not frequently retime 
the transmitter or receiver, it is 
easy to use. Certainly there is 
adequate space to stretch your entire 

forearm on the table to make sending 
with a hand key easier, and there is 
sufficient room to work with scratch 
pad and log books. But can you sit 
there for a lew hours staring straight 
ahead at eye level. Staring at the dials? 
I would imagine that your back would 
hurt from sitting erect so long and 
alternating with leaning over while 
sending. And if you have to retime the 
receiver or transmitter frequently, as 
in ;j contest, your arm will have to be 
raised to turn the knobs and your 
shoulder will ache. If the rig is at a 
certain height, your elbow will bear 
the weight of the arm that it supports. 
Lowering the rig might help to relieve 
some of the physical pressures of 
operating overextended periods. 

Raising the rig has its attendant 
problems too. If it is too high, the 
forearm will be supported by the 
muscles in the upper arm and a lot of 
weight will be balanced at t lie elbow. 
Your arm is like a lever and if the load 
(the hand and forearm) is long and the 
opposite side of the lever ts short 
(yt)ur upper arm is almost vertical as 
you sit at the table h muscles in the 
arm and shoulder will soon ache and 
the elbow hurts. Lowering the rig to a 
point where the forearm can rest on 
the operating desk and knobs can be 
turned with a thumb or a couple of 
fingers will help a lot in easier opera- 
tion. This arrangement also offers the 
advantage of having the gear next to 
your hand as your a nn ami hand are 
relaxed. 

Are you right or left- handed? Do 
you tune your receiver often? Is the 
main tuning knob close to the hand 
that can more comfortably turn the 
knob? Some receivers have the tuning 
knob close to the left side of the 
receiver and if you are right handed, 
you will have to reach across your 
body to operate iL By reaching across 
your chest, you constrict your ehesi 
and breathing becomes a little more 
difficult. It may not be too noticeable 
at first, but after an hour or two. you 
begin to feel a little fatigued from 
cramping your lungs and breathing 
muscles. If the desk is not too wide, 
put the less frequently used equip- 
ment above but not so close thai 
rising heat causes problems with stabi- 
lity. 

Lo ud spe a k e r a nd headphones 
should be within easy range, the 



fREPEATER UPDATE 

LISTENING 

94 76 88 73 70 64 82. . . 



- 




CT WAT NOP Naugatuck 444.2-449.2 

CT WA1KGO Vernon T9-79 

52.76-52.525 
443-3-448.3 
221.38-22438 
IN W9CSF Michigan City 

Incorrectly lifted in Jan, as W9Cf 

Recent changes are 1.8 kHz TB or 131.8 Hz PL 
MA WA1KHB (formerly W1HWKI 
MA WA1KHC (formerly W1CSF) 
MA WAMHN Somervifle 07-67 

MA W1RJS Salem 28-88 

(formerly W1ZAW Beverly) 
MA W2EM8 Evereit PL 88.5 Hz 13-73 

MN K0LAV St. PaylWI.4 34-94 

NJ WA22VQ Torm River 31-91 

NY K2LEQ Delete 

OH WBCQR Cleveland 16-76 

Rl WTHGV Providence 16-76 

TN W4SS Memphis 22-76 

Wl W9VZR Milwaukee T2.1 29.440-29.600 



Navy MARS repeaters are linking 
on a coasl-to-eoasr network. The 
latest informu tion is fchaJ they arc 
using input and output frequencies of 
148.41- 150,09; AF MARS use* 
142.155 143.4(k and Army MARS 
uses 1 43.35-14801. 

Tnx to KDLAV. WIHQV, k^DZH. 
KIKRY. K3ZQN. K4ZZO. W9BLR. 
W1GAN.W2fcXQ. 

When you hear a now repeater on 
i fie air, drop us a line and we'll share 
the news. If you hear of one going oil' 
the air, let us know also* please. 

National 52 Simplex 

The move toward using 5 2 as a 
national simplex frequency got sup- 
port from the repeater groups of the 
Northeastern US. at the meeting of 
75 repeater groups in Westchester 
(PA) and. about 50 groups in Shrews- 



speaker sueh C hut it does not semi 
sound to only one ear, and the cans in 
a position that they can be quickly 
reached and plugged in. Paper. log. 
pencil all have their plaoe too. Light- 
ing should he not too strong or weak 
and preferably it should be indirect, 
that is, reflected off a wall or ceiling. 
Avoid glare. 

Ham radio is an enjoyable hobby so 
do not make it physically hard to 
enjoy it. Station arrangement Tor con- 
venience and comfort is an art. Think 
o\ how much each piece of gear will 
be used in comparison to each other 
piece. Are frequently used items 
handy or buried in a drawer? Taking 
the time to set up everything for 
comfort helps to enjoy the art of 

communication. 

And do not place your station in 
front of a drafty window; 

., .K1NUN 



bury (MA) early this year. All agreed 
to the 5 2 transeeive channel. Add this 
to the similar agreements in the mid- 
west and you have a movement. 

With the hope o( encouraging this 
idea 73 wrote to the manufacturers oi 
FM transceivers and asked that the) 
consider including 52 pairs in their 
sets in the future instead of 94 pairs. 
Several manufacturers were enthusi- 
astic about this and as present stocks 
of the l *4 crystals get down to reason- 
able levels the new 52 pairs should 
start getting into service, Many manu- 
facturers indicated that their cus- 
tomers have only to write to them and 
an exchange of crystals can be made 
at no charge. 

To encourage the move to 52 
simplex 73 will publish ;i box score 
for the next few months listing all sets 
which will be coming out with the 52 
pair 

Why the big push for 52? This 
should take some of the pressure off 
the use of 94 as a simplex frequency. 
The 94 pairs of crystals in sets has 
resulted in heavy simplex use of this 
channel in the larger urban areas and 
this causes trouble with 34 94 re- 
peaters. All you need td do in the 
New York area is hint at a new 34 ''4 
machine and 94 will turn blue as the 
emotions pour out, obscuring reason 
from 88 up to 97 or so. 

The fact remains that there are 
more 34 94 repeaters than any other 
and they are not going to be wished 
away by New York or Los Angeles or 
the other big urban areas* 

With the cooperation t^l crystal 
companies and transceiver manufact- 
urers the change to 52 can be made 
during the next few months. Inexpen- 
sive crystal pairs fpr 52 will help. Free 
exchange of crystals by manufacturers 
will help. Cooperation will help most 
of all. Does it really make sense to 
sound off endlessly about getting re- 
pealers off 94? The view from Jack- 
son Heights (NY) may tell you that 
just about everyone in the world is 
using 94 as a transeeive frequency and 
everything would be just great if those 
crumbs over m New Jersey would just 
move that repeater in Greenbrook. A 
look at the repeater list in this issue 
will tell you the big story of the 
multiplicity o( 34 94 repeaters a- 
round the country and the virtual 
impossibility of getting ""all repeaters 
off 94*" Perhaps 52 is the better bet 

Derrick Electronics in Broken Ar- 
row OK will supply crystals tor all the 
commonly available rigs for only 

7.75 per pair. Converted commercial 
rigs are slightly more. Derrick is the 
first supplier to indicate this Type of 
support for a national simplex fre- 
quency. Sonar Radio will supply any 
crystals to the users of their products 
as substitutes for 34 94 and 94-94. 



9 




EDITORIAL BY WAYNE GREEN 



OUR PROFILE 

It should be no news to amateurs 
that CB groups have been stealing the 

thunder from us as far as public 
service is concerned. The communica- 
tions provided by a group of CBers 
with mobile units is fine Tor most 
local arc;i situations and in most parts 
of the country CB lias been putting 
amateur radio to shame. 

The size and expense of amateur 
radio equipment for the low bands has 
been such that interest in mobile 
operation has dropped tremendously 
over the last twenty years. In the old 
amplitude modulation days a little 
mobile converter and low powered 
transmitter weren't a big deal. The 
converter played through the car radio 
and worked fine. Then came sideband 
and a whole new ball game as far as 
stability and complexity was con- 
cerned. And out went wholesale 
mobile operation as we knew it in the 
early SOY 

Mobile operation is back, stronger 
than ever, but it is on two meter FM 
now and works through repeaters. We 
have better communications than we 
ever had before, so how about using it 
for public service? We can now r ^i Ik. 
base to mobile to hand unit over a 
range of about fifty miles from most 
repeaters, ideal coverage for most lo- 
ll applications. 

Okay, we have the facility, how do 
we swing into gear with It? How can 
we make this pay off for amateur 
radio 4 ? 

The number of events and situa- 
tions which can use good communica- 
tions is endless... it can be almost 
any sporting event such as boat races, 
bicycle races* ski races, en country 
races, car hill climbs, car rallies. 
parades, telethons, etc, All you have 
to do is keep your ears open and gel 
the member of your repeater group to 
keep on watch for opportunities to 
serve. 

Providing service is fun , . . a lot of 
fun. You'll be right in the middle of 
what's happening and youll be work- 
ing with the people who are running 

the event. You may find yourself 
parked in an out-of-the-way spot 
along with a small team of timers on a 
rally checkpoint. Your job will be to 
send the times of the cars passing 
through the checkpoint back to the 
njllymaster so he can compute the 



scores. You may well have to do this 
for two or three different checkpoints 
through the day if it is a long rally. 
The chances are that youll emerge 
from this job with a strong interest in 
rallying. 

Serving is fine, but please don't 
forget that the service is only half of 
the work. You may be self-effacing 
and not want to blow your own 
trumpet over what you've done, but 
amateur radio needs all the credit it 
can get so put your modesty aside and 
let the local papers know what you 
are going to do, what you are doing 
and what you have done. Also iilert 
the local radio and television sta- 
tions ... get good PR for amateur 
radio. And ■ . . please . . , send a copy 
of the newspaper item to 73 when 
you get done so we can perhaps make 
a mention of it in our newspages , . . 
we send reprints of the better news- 
pages to Congress. 

HIGH POWER BASE STATIONS 

Repeaters are designed to work 
with mobile stations running on the 
order of ten watts. Most of them will 
give coverage of about fifty miles or 
so under these conditions. So what 
happens when someone comes along 
with a home station running 250 
watts plus a nice big beam w T hich steps 
that up to about the same signal a 
5000 watt mobile would put out? 
Chaos. 

A big base station can lift repeaters 
for a couple of hundred miles around 
and put several out of business while 
making a local contact. 

If you have a big signal base station 
please keep in mind that it is within 
your capability to ruin the fun for a 
lot of people when you are inconsider- 
ate. Fellows will go along with you on 
an occasional band opening, particu- 
larly if it isn't at the peak operating 
hours, but don't be in there night 
after night wiping out repeaters in the 
next state just because you don't care. 
Fun is the name of the game . . . fun 
for as many people as possible* So 
don't spoil the fun. 

PRIORITY INPUTS 

One of the grumbles frequently 
aired by FMers who have come into 
ham radio via the two-way communi- 
cations route is that too many base 



stations take up repeater time and 
don't let the lower powered mobile 
stations get a word in. Now and then 

there is a case where a real emergent} 
corner up and long-winded higher 
powered ops just won't shut up long 
enough to let a breaker get through 
with emergency traffic. 

Rather than go the route of 
freezing base stations out of repeaters, 
perhaps we might think of the 
situation in terms of needing more 
repeaters, not less activity on the ones 
we have. Until all of the two meter 
and even the 220 MHz repeater chan- 
nels are full and active, we do have 
room for repeater expansion. 

Emergencies and low powered mo- 
bile entry into repeaters can be solved 
by setting up a second receiver at the 
repeater site with a priority hookup so 
it will override the regular base station 
input channel One reader has gone so 
far as to suggest that a "national" 
emergency calling channel be set up 
which would override all repeaters. We 
could set aside one channel for strictK 
emergency traffic input and have it 
take over all repeaters in range, but 
this would require an awful lot of 
cooperation on the part of the users 
to keep the hell off thai channel 
except when the emergency arrive 
Perhaps that is too much to ask. 



COLLINS KAPUT? 

Apparently no decision has yet 
been made by the Collins management 
about the future o\ the amateur radio 
division. Rumors are, of course per- 
sistent that Collins will close down 
their amateur radio manufacturing. 

Collins, once leading the industr 
with new designs for amateur equip- 
ment, seems to have stopped their 
development about ten years ago at 
the time of the ARRL petition to the 
FCC which eventually resulted in tlv 
downgrading of most amateur 

licenses. 

This is a far cry from the days when 
Collins had just brought out the 75A1 
and the 32V 1 and were busy selling 
the advantages of sideband to the Air 
Force, Old-timers will remember the 
many flights around the world made 
by Art Collins W0CXX with Mort 
Kahn W2KR and a handful of other 
"important" hams made in Air I orce 
planes with Generals Butch Griswald 
and Curtis LeMay, These chaps talked 
with their small group of friends on 
the high end of 20m phone, continu- 
ing the 'private club" type of ham 
radio so popular on the high end of 
75m during the 30*s. 

Perhaps this is exaggerated in niv 
mind, but I seem to recall that as part 
of the effort to sell the Air Force on 
Collins sideband equipment, their ham 
gear was installed in just about every- 



10 



thing General LeMay had thut moved 
or was around him . . * home, car* 
plane, boat . . . etc. However the sale 
was made, it seems to have worked 
and millions of dollars of Collins gear 
was bought by the Air Force, or was it 
billions? 

Somehow, though the equipment is 
the oldest still being marketed for 
amateurs, Collins equipment still has 
prestige. It certainly was line in its 
day. The cost of redesigning would be 
very high now and there seems little 
likelihood that the new Collins 
management, strapped for cash, would 
find it worthwhile to make the invest- 
ment required to continue to sell in 
the static sideband ham equipment 
market. FM is the big one in 1 ; >72 and 
in that field Collins would be starting 
almost from scratch and would be up 
against those little transistor radio 
makers from Japan, 

What will happen to used Collins 
prices if the factory closes down the 
dealer setup? This could have serious 
effects once parts and repairs are hard 
to come by. 

Being practical about it, there 
seems little possibility that Collins will 
continue to make ham equipment. It 
is sad to see another top name in ham 
radio go. 



Old-timers do not have any corner 
on the market when it comes to 
grumbling about how bad things are in 
the ham bands. The Nattering Nabobs 
of Negativism are souring away, bad- 
mouthing the Inconsideruteness on 
twenty meters, the lids on six, the 
base stations who talk at length over 
repeaters, and so on and on and on. 

Perhaps it is the old psychological 
mechanism known as projection that 
they are seeing. It is just possible that 
the reason they are complaining so 
bitterly is that they are laced with 

themselves at every turn and don't 
ever see anvone else. 1 hat's enough to 
turn any stomach. 

Is there a pat answer to this? An 
easy solution*' 

I think so. The next time you get 
regaled with sighs and groans about 
what our bands are coming to. suggest 
(tactfully) that said griper try finding 
out a bit about the chaps tluil he talks 
with the most. He could make up a set 
of index cards or a file folder with 
notes on each regular contact . . . full 
name, wife's name, names ot children, 
what all of them do, other hobbies of 
his and his family, places he has visit- 
ed, what equipment he has and ma\ be 
what he is thinking of getting, notes 
on any interesting yarns he has told, 
what other ham interests he has, 
bands he works. 

Such a file will serve several pur- 
poses. Getting the information will re- 



sult rn some of the most interesting 
contacts the other fellows have ever 
had . , and they will comment on 
this. People like talking about them- 
selves more than anything else in the 
world. Your curmudgeon will soon 
find that, once he knows more about 
iho chaps he h;is l>een tulkint: with, he 
will enjoy the contacts a lot more. 
They will be with people, not just call 
letters. 

Can this system fad? Probably, but 
you'll have to prove it to me by trying 
it first. 

73 TOUR OF EUROPE 
IN SEPTEMBER 

How would you like to walk 
around Moscow with a transceiver and 
work a bunch of amateurs over there 
with you on a tour? Special per- 
mission lias been requested to permit 
U.S. amateurs to visit Moscow this fall 
and bring along their two meter trans- 
ceivers . . . plus permission for 73 to 
bring along a complete small repeater 
unit and set it up so we can all keep in 
touch from anywhere in town. Will 
that be fun? 

The trip is scheduled to start Sep- 
tember 4th from New York and fly 
first to Copenhagen . . . Tivoli amuse- 
ment park will be open . . . some of 
the finest restaurants in the world . . , 
and REAL Danish pastry ... or 
would you rather take a look at those 
sex shops? We 1 !! arrange for you to 
meet Danish amateurs and visit with 
them . . . perhaps a nice ham f est and 
party. We expect no problems setting 
up a repeater here > . , nor with getting 
permission for all of us to operate. 

The second stop will be Berlin, with 
organized tours (if you like) of both 
East and West Berlin. Other than this 
there will be no organized tours. You 
will be flown to a city, taken to a nice 
hotel, and provided with break- 
fast . . . from there you are on your 
own. We'll recommend restau- 
rants ..... get you in touch with local 
amateurs , . . and give you the benefit 
of our experience. 

The third stop will be Moscow 
where we will meet many of the local 
amateurs . . . and have a party with 
them. We hope to arrange it so those 
interested in working DX will be able 
to operate some of the club stations 
and talk back home. 

The last stop will be Amster- 
dam . . , more amateurs . , . hopefully 
a party ... and more two meter fun, 
probably with our own repeater. 

The trip will laM three weeks and 
will be something you will remember 
the rest of your fife. Nothing like this 
has ever been done before , . . how 
about coming along? 

tn order to keep the price of the 
trip as reasonable as possible we will 
be staying at good hotels, but not 
posh ones. We have always found that 




NEW PRODUCTS 



NEWGE VARISTOR 

Voltage surges burning up your 
transistor projects? Need some kind of 
protection on an \C that is ea>ily 
ruined by excessive voltage? The 
answer to the problem is the new 
GE-MOV varistor made by General 
Idee trie. By mounting this device in 
parallel with the delicate components 
or circuit the MOV acts as an insulator 
until a voltage surge occurs. Then the 
MOV becomes a conductor and the 
power is safely bypassed from your 
circuit. The MOV. short for metal 
oxide varistor, can be used for pro tec* 
tion. Stabilization, or regulating volt- 
ages to components like ICs that can 
melt with too much voltage. As tech- 
nology advances, these devices will 
find greater acceptance in the home- 
brewer's shack, but in the meantime. 
they will be used in industrial applica- 
tions such as TV. relay and motor 

— 

protection, and other places where 
solid state controls are found. We'll be 
hearing more about this in the near 
future. Contact the Semiconductor 
Products Dept., General i.Ut trie Co , 
Building 7 t Mail Drop #4 ( A Electron- 
its Park. Syracuse NY 13201, 

{continued on page 12} 



the smaller hotels are much more 
friendly and Win . . . better food . . . 
better service ■ . > and an interest in 
you. You can have the snob places 
where the desk clerk has a permanent 
sneer. 

fhe whole trip, based upon double 
occupancy of rooms, with bath where- 
ver possible, including all air and land 
transportation, airport taxes, break- 
lasts, parlies, is expected to run about 
$700 each . . . SI 350 for two. 

If you like the idea and want to re- 
rve a spot on this trip you may send 
in a check for $200 down payment 
for each ticket. This is refundable in 
full up until (>0 days before the trip 
and in part after that, final payment 
will have to be 60 d;iys before de- 
parture. Please sign up early so we will 
be able to handle the amateur radio 
license registrations and permits for 
the four countries. We'll send you 
crystal information for your trans- 
ceivers to match our portable repeater 
as well as the many repeaters now on 
the air in Europe. 

Three solid weeks with Wayne 

Green? Lordy! .W2NSD/1 



1 1 



NEW PRODUCTS 

Continued from page 1 1 

SINGLE FUNCTION METERS 




Experimenters will really like the 
new single function meters made by 
ALCO. These meters have multiple 
ranges, but each is made for only one 
function (i.e,, dc microump, dc milli- 
amp, dc amp. dc volt, ac milltamp, ac 
volt, and ac amp). Each meter has a 
wide face, making reading easier, and 
the accuracy rating is 1 .5%. Low cost 
makes these easy to own, as the 
average price per meter is about thirty 
dollars Write to ALCO, 155 I Osgood 
St. North AndoverMA 01845. 

NEW 220 TRANSCEIVER 

CLEGG 2 ler: the first 220 MHz 
FM transceiver offering the operating 
features and quality performance that 
FMers have come to expect on lower 
frequency bands. 

The 2 ler provides automatic panel 
selection of ten primary crystal eon- 
i rolled fcransm it-receive channels and 
secondary continuous tuning of the 
220 MH7 I M band. The 2 ler provides 
a conservative ten watts output com- 
bined with a .25 jiV receiver with the 
ruggedness and reliability of an ex- 
truded frame and diecast panel struc- 
ture. 

Scheduled for production in June, 
the 2 ler will be priced under S3D0. 
Also planned for early release are 
220 144 MHz receiver converters and 
220 MHz repeater package, 

6-12 VOLT DC CONVERTER 




Solitron Devices. Inc., announced 
the release of a h 12V dc converter 

for use with vehicles having a 6V 
negative ground system. The converter 
will step up a 6V dc source to I 2V dc 
for use with the newer electronic 
accessories now available for the high- 
er voltages. The converter can be used 
to supply 12V dc for use in powering 
AM-FM radios, auto stereos, tape deck 



equipment, amateur communications 
equipment, and other accessories. 

The converter also has ft amp out- 
put continuous, a switch and pi- 
lot light to insure converter is work- 
ing, puts out up to 72W, has a one 
year warranty, and fits conveniently 
in trunk area or under dashboard of 
vehicle. For further information eon- 
tact Solitron Devices, Inc.. 256 Oak 
Tree Road. Tappan NY 10983. 

LOW COST IX. POWER SUPPLIES 

Viking Electronics, Inc. has intro- 
duced a line of low cost power sup- 
plies for logic and linear system appli- 
Etioris. Priced from SI 7 to S24 in 
single quantities, the OEM 70 Series 
provides typical outputs of 3.5 to ftV 
3 amp, 8- 15V & L2 amp with 
regulation of .5 to J'* and ripple of 1 
to 2MV dependent on models- 
Features include electronic current 
limiting, floating output, stable differ- 
ential amplifier circuitry, silicon tran- 
sistors and computer grade capacitors. 
For more information contact 
VIKING ELECTRONICS. INC., 721 
Sl CmixJludson WI54016. 

IMPROVED TEMPO FM AMPLIFIER 




ln January we reviewed the Tempo 
100 watt amplifier. , . just in time to 
find that a new model had been 
released which was even better in 
almost every way ! 

The Tempo amplifiers are made by 
TPL Communications in Hawthorne, 
California, not in Japan like the 
Tempo FMV transceiver. They were 
formerly made by CT, Power, but the 
company was reorganized and now is 
owned by Tom Ljtty K6RAD, a 
young designer from" TRW, the com- 
pany that makes most of the power 
transistors used in the power ampli- 
fiers on the market today. 

The new 120 watt amplifier has 
printed circuit coils, with about the 
only things sticking up at all being 
small lumps for the driver transistor 
and the three parallel output transis- 
tors, some Hat by*pas> capacitors and 
small tuning capacitors. With 10 watts 
in you definitely do get 120 watts 
out this is exactly what I measure in 
my car using the Standard *2ftM as a 
driver; It does make a difference too! 
With the ten watt signal I can general- 
ly Mil repealers that are coming in an 
S-4 or so the 120 watts puts me 



through repeaters that are less than 
S-l , but still are readable 

If all of my contacts were made 
parked on the top of my nearby 
mountain. 1 wouldn't have much use 
lor the higher power. But one of the 
problems of living in the mountains is 
that most of the time I am driving 
with a mountain between me and the 
repeater I am talking through- This is 
where the power helps a whole lot. 
After all. if I can hear the repeater, 
why shouldn't I use enough power to 
get into it from wherever 1 can hear 
it? That seems reasonable to me and 
the 120 watt Tempo does this job 
beautifully, 

Tom has added some other extra to 
the new T amplifier; little plus details 
There is now a jack for plugging in a 
control switch to turn the amplifier 
on and off, keeping down your bat- 
tery drain when the extra power 
output isn't really important. Once 
your repeater is coining in over S-ft or 
so you probably won't need the pair 
of shoes and your car may appreciate 
holding onto the 1 7 amperes. 

Perhaps it's a small thing, but 1 
appreciate the addition of a power 
output plug instead of a cable hanging 
out with a UHF connector on it. Once 
the unit is in place under the seat of 
my car it doesn't make any difference, 
but when I go lo take the amplifier 
nut for a trip (j take it with me when 
1 fly and use it in rented cars), it 
greatly simplifies the change. 

The FPL amplifiers wen -»n display 
it SAKOC and were one of the hits of 
the show! The wattmeter used for the 
demonstration showed that the ampli- 
fiers were rated conservatively and 
that 140 watts out of the 120 watter 
was not uncommon. 

The promised 220 MHz TPL trans- 
ceiver drew much attention too and is 
due to be produced soon. Hie com- 
pany reorganization put them back a 
lew weeks There are* I understand, 
well over 200 back orders for this 
unit, so perhaps we will start seeing 
serious 220 activity in the near futurv 
The most important product promised 
from TPL is a 220 MHz repeater. 
Once that is available we can start 
populating the band in earnest. I look 
forward to the day when virtually 
every repeater club has a 220 MHz 
repeater as well as one for two meters. 
TPL has quite a wide range of 
amplifiers for two me l e is, six meters, 
220 MHz and 450 MHz. I heir two 
meter amplifiers are designed to work 
with any of the commercial trans- 
ceivers, from the one watt output 
Drake TR-22 up to the 25 watt 
Gladding and Simpson units. They 
even have an amplifier that will lift 
the TR-22 to 1 00 watts out. 

Distributors would do well to con- 
tact Ik'nry about handling this line of 
equipment W2NSD I 



12 



SOCIAL/^ 
EVENTS f 



Till 



CONTESTS 



F/'J 



» 



The Radio Association of Eric, OH 
April 8, will hold its annual Ham 
Auction at the St. George's Gym. The 

auction starts at 2:00, and it is expec- 
ted to be a good one. The gym is 
located 1 Vi miles north of 1-90 on U-S, 
Route 19. Free map and details from 
RAE Auction. Box 844. Erie PA 

16512. 

* * * 

The Southern Tier Radio Clubs are 
sponsoring their Thirteenth Annual 
Hamfest tor April 15 at the St. John's 
Ukranian Hall Johnson City NY at 2 
P.M. For tickets and additional in tor- 
mat ion. contact John Pike WA2UK5. 
635 Laeey Dr„ Endwell NY 13760. 

* * # 

The Delaware Amateuf Radio Club 
will hold a Horse-Trader and Auction 
night at the County Engineering Bldg., 
Kirk wood Highway, Wilmington, 
Delaware on Wednesday April 12 at 8 
P.M. Bring your gear and sell or swap. 
For further information contact 
Charles M eGoniga I W A 3 A V D , 18 
Harvard Road, Wilmington DE 1980S. 



* 



* 



mon&trations. Ladies, luncheons and 
imirv Pre-regist ration prize plus other 
prizes. Swapfesl. auction, and other 
activities on the 30th. Plan to enjoy 
the hospitality and fun in the sun. 
Contact Al Summers W7MGF, Chair- 
man, e/o O.P.RC Box 6497, Tucson, 

Arizona 85716, 

* * 

The Young Ladies Radio Club of 
Los Angeles will hold its Sixth Inter 
national YLRL Convention, Tours, 
cruises, talks, meetings, and entertain- 
ment will fill the long holiday week- 
end of May 26, 27 and 28. The 
convention will be held at the Edge- 
water Hyatt House on Pacific Coast 
Highway overlooking the Long Beah 
Marina. Registration of SI 2.50 goes to 
SI 4.00 after May 15 Further infor- 
mation can be obtained from the 
Convention Committee. PX>, Box 
3092, Long Beach CA 90803. 

* * # 
The Fresno Ainateur Radio Club 
presents Fresno Hamfest '72 on April 
28, 29, and 30. There will be swap 
tables, transmitter hunts, displays, 
banquets and more. The convention 
will he held at the Fresno Hilton, 
Listen in on 7255 WCARS and 3952 
WTSS, or write to Fresno ARC. P.O. 
Box 783. Dept. HF, Fresno CA 93712 
for more information. 



The Fresno Amateur Radio Club 
presents Fresno Hamfest *72 on April 
28. 29 and 30. There will be swap 
tabic > transmitter hunts, displays, 
banquets and more. The convention 
will be held at the Fresno Hilton. 
Listen in on 7255 WCARS and 3952 
WPSS, or write to Fresno ARC, P.O. 
Box 783. Dept, HF, Fresno CA "3712 
for more information. 

* * * 

The Rockaway ARC will hold its 
Annual Spring Auction and FMers Get 
Together Friday evening April 28. 
1972 at 8:00 P.M. at the Hall of 
Science. 111th St, & 48th Ave., 
Carona. N.Y. at the old World Fair 
grounds. Doors open at 6:00 P.M, to 
accept items for the sale. Two dollar 
donation at the door will include 
refreshments. For further information 
contact Auction Chairman, Al Smith 
WA2TAQ,.P.O, Box 341, Lynbrook, 
N.Y. 11563. 

* * * 

Southwest Ham Round-up and 

Fiasco will be sponsored by Old 
Pueblo Radio Club April 29 30, 
1972, Headquarters Ramada Inn, 
Tucson AZ. Banquet, technical ses- 
sions with ham applications and de- 



GEORGIA QSO PARTY 
Starts: 2000 GMT, Sat., May 13, 

1972. 

Ends: 0200 GMT. Monday. May 15. 

1972. 

The eleventh annual Georgia WSO 
Party is sponsored by the Columbus 
Amateur Radio Club, Inc. There are 
no time or power restrictions and 
contacts may be made once on phone 
and once on CW on each band with 
the same station. Bach complete con- 
tact counts 2 points, Georgia stations 
multiply their total QSQ points by 
number of different states and 
Canadian provinces worked. DX sta- 
tions may be worked for QSO points 
hut do not count as multipliers. 
Out-of-state stations will use the 
number of Georgia counties worked 
for their multiplier (a possible total of 

159). 

Write to CARC. Inc.. Attention: 

John T. Laney K4BAL P.O. Box 421. 
Columbus GA 31902 for full informa- 
tion on the contest. 

MARYLAND 

Potomac Area Ha mi est will be held 
at Westminster. Maryland, on Sunday. 
April 30th. 9:00 to VOQ £2 registra- 
tion covers flea market and tail-gate 
>ales. Professional food and beverage 
catering on grounds. Parking for 400 
cars Usual hamfest activities. FM 
talk-in on 140,94. Details from 
K3LNZ, K4LlIBoi W3EVF. 



1972 NEW YORK STATE 
QSO PARTY 

This contest is open to all amateurs 
and SWL'sin the world. 

Times: 1 700 0500 April _ n ' 
through April 30 GMT; 1 200 2350 
April 30 GMT. 

Calls: In State: CQ NY TEST; out 
of State: CQ NY. 

I \ change: Q so number. RS(TL 
QTH out of state stations use 
ARRL sections; NY stations use 

counties. 

Scoring: Score one point per con- 
tact on 80 I'd; two points for each 
160, 6, or 2 meter contact: times 
number of multipliers. 

Logs must contain date and time, 
band, mode, station worked, QSO 
number. QTH first new contact for 
each multiplier numbered. 

Certificates will be awarded to top 
scoring station in each ARRL section, 
country, and NY county. Special 
Novice and Technician certificates will 
also be given. Second and third place 
awards will be issued at the discretion 
of the contest committee. 

Logs, comments photos, etc. 
should be sent no later than June 1 to 
LLRA ARC/ Contest Committee, Jell 
Runner WB2ALQ, 35 Gottlieb Drive, 
Pearl River NY 10965. Stations plan- 
ning operation in NY are urged to 
contact LERA so they can plan for 
coverage of all counties. 



THE FOURTH RTTY 
WAEDX CONTEST 

RTTY WAEDC '72 

The Deutseher Amateur Radio Club 
(DARCK the sponsor of the RTTY 
WAEDC. and the Deutsche Amateur 
Fernschreib Gruppe (DAFGL the 
manager of the RTTY WAEDC, have 
the honor to invite RTTY amateurs all 
over the world to participate in the 
4th RTTY WAE DX Contest 1972. 
This contest is always held on the last 

weekend of April. 

| CONTEST PERIOD: April 29, 
0000 GMT to April 30. 2400 GMT. 
2, CONTEST CALL: CW WAE de - 
3 SCORING: The final score is the 
total QSO points plus QTC points 
multiplied by the sum total countries 

from all bands. 

Contact WAEDC officials for fur- 
ther information: WAEDC - Commit- 
tee, &S95Q Kaufheurvn. PO. Box 

262, Germany - West. 

COLUMBUS GEORGIA HAMFEST 

The fourteenth annual Columbus* 
Georgia, hamfest will be held on April 
9, 1972 at the Fine Arts Building 
behind the Municipal Auditorium at 
the Fairgrounds. For information, 
write J. T. Laney. K4VGL 1905 Iris 
Drive, Columbus GA 3 1 906. 

(continued on page 14) 



13 




According to the Mobile News the 
Journal of the Amateur Radio Mobile 
Society, the following members have 
attained now status in the Mobile 
Century Award Listings: WnKZL/in 
236, F3DJ/rn 221, G3BIP ni 20 1, 
SM5RQ/m 190, DL6UH [« 
W4NLW/ m 140, G3TJY/m I2L 
W\3HDU.'m 108, G3KNB/ra 103, 
WA4WIK m 102, and DJ3LF/mand 
WA2FQG/m T |()i apfece. 

ffltf reports m the DXers Magazine: 

W3QLW has received the Arabian 
Knights certificate which stales on a 
beautiftt! document* "The Arab Radio 
Amateur League has ihe pleasure to 
certify that Mr- Oscar G. Herrick, 

W3QLW, has contacted ten Arab 
countries and has been granted the 
Arab Knight award in significance of 
being a dear friend to all Arab Radio 
Amateurs. League Chairman (signed 
Hussein, JYLj Date 30 Sept, 1971 No. 

C3 I DP will he active for three 
weeks in June, so says Omer ON 5 TO 
who should know; it is his second call 



SOCIAL EVENTS & CONTESTS 
(continued from page IS) 

7th WORLD ORCHID CONFERENCE 
AMATEUR RADIO CONTEST 

I he contest has been organized by 
the "Liga Colonibiana de Radio- 
aficionados, (Zona 4a) and is spon- 
sored by the 7th World Orchid Con- 
ference, It begfns at 0000 GMT, Satur- 
day April 8 f 1972 and ends al 2400 
GMT, Sunday, April L >. AM and SSB 
in phone only. 5J4LR and 5K4LR 
will also be on (he air. Multi-operator 
stations not allowed. Exchange: MK4 
st.i I inns, RS plus a 3 figure number in- 
dicating the power of the station. 
Other stations, RS plus a 3 figure con- 
tact number, starting with 001, 

Points: For stations not in North. 
Central or South America —contacts 
with HK4 stations. 5 points, con tad 
with 5J4LR or 5K4LR. 10 points. For 

i lions in North. Central or South 
\mcrica - contacts with HK4 sta- 
tions, 3 points, contacts with 5J4LR 
or 5K4LR, 5 points. 

The same Station may be worked 
on each band for multiplier credit. 

Final score: the result of multiply- 
ing the total number of points by the 
number of bands worked. 

Mailing deadline: June 9, 1972, to: 
LCRA. Seccional Medellin, Apartado 
aereo 51900* Medellin, Colombia, 
South America. 



Between Fit, W8KGR, and Guy, 
TRSDG, the French Community Net 
is handled very well. The net meets on 
Mondays and Wednesdays at P>30Z 
on J! 1 J390* Plans are to increase activi- 
ty to four days per week operation 
and they want many cheek-ins. 

If you are looking for TN8BK, try 
around I400Z near 21330 up. As a 
doctor, Be nurd docs not have too 
much time for operating. 

Les, ZD9GA, has been active from 
Gough Island on 20 SSB. Most o\' his 
operating seems to be list type work. 
QSLvia /S2RVL 

7X2BK has been heard on 20 SSB, 
around 14,2 : tbout 2000Z. Listen 
carefully as he is using transceive and 
an indoor antenna. 

Even Wednesday Robert, 1 >U5CR, 
holds skeds with his QSL manager 
Omer, ON5TO, at 180DZ on 14.280, 
He is QRV for others alter they are 
finished. 

Tapei is active now that BV2AB. 
Bob, is on the air. He is ihe first 
American to be licensed there in 
several years, Look for Bob 1 4,230 
from 2300 013QZ. Sends QSLs via 
K4ASL 

Contact Mary. WA3HUP. if you 
need help in working CR3KD on 
Portuguese Guinea, "They have skeds 
twice a week on 15 and 20. 

Nauri Island. C21TL, can be found 
14,200. This station will be on the air 
for about three years. FB8ZZ, on the 
other hand, will only be active for 
another month or two. FH8CG can be 
heard near 21,285 about I700Z. And 
FM7AA is at 14,222 about 1240Z. 

JX2HK has been worked on 
14,038 about 2000Z. This is Jan 
Ma yen Island, 



From CARF, we learn that , , . 

ONI A R S Ontario A m ateur 
Radio Service lias commenced opera- 
tion on 3775 k M/ . Hours of operation 
are from 7 AM to 6 PM E(D)S1 . daily. 
This is a call-in n^t similar to EGARS 
on 40 with the prime objeel of pro- 
viding two-way facilities during the 
daylight hours throughout Ontario, 
Congrau la lions go to the Radio So- 
ciety of Ontario for sponsoring the 
net and to Bruce Carvelh VE3BC. 
ONTARS net manager. 



And from the West Coast DX tin He fin . 
An international group claims to 
have established an away-from-il-all 
republican state on the desolate sea- 
washed Minerva Reefs in the Pacific 
about 450 miles south of Fiji. Fiji has 
been asked to recognize the state, 
established by the self-styled Ocean 
Life Research Foundation of New- 
York and London. Two dredges are 
due to arrive at the reef in three weeks 



to befijn reclaiming up to 400 acres of 
land on Minerva. Mark Oliver, a U.S. 
Citizen who said he is one of the three 
directors of the foundation, said in 
Suva their intention was initially to 
build a port and later a sea city as a 
haven for people who wanted to 
escape from crippling taxes, riots, 
crime and drug addicts. "We decided 
on Minerva after a worldwide search 
because research showed conclusively 
that the reefs do not belong to any- 
one/' he said, "By International Law 
one can claim by annexation only 
land above the sea that can be built 
upon. We have met this requirement 
by constructing two small islands of 
coral and %and on the reefs." Oliver 
said the Ocean Life Research Founda- 
tion, established IK months aco and 
backed by scholars throughout the 
world, was serious about a sea city 
republic at Minerva. International en- 
gineering companies had been eonsult- 
ed ;iud expenditures on the project; so 
far. totaled $180,000, he added. 

* * * 

QSLs for 3D6AO. Swaziland, may 
be sent to P.O. Box 1 . Mhlume 
TshanenL N.E. Swaziland. 

Nigerian Amateur Radio Service 
and Joe, 5N2AAJ only accept incom- 
ing QSL cards for Togo, 5VZ and TJ 
and they are not responsible in any 
way for outgoing QSL cards. All 
incoming cards are passed on to 5VZ 
immediately and after that their re- 
sponsibility is ended, 

The Liberian Radio Amateur 
Association sponsors a West Africa 
Net on 7060 at 0800Z each Sunday. 
So far 9G1, El 2. 914, and 5V7 have 
joined in. 

♦ * * 
Some of the current active ' DX 



pedition of the 
HP tit 3FUE, 
PJ7VL, VA2UN, 
VK9XK, VP8JV. 
and 9Y4VT, 



month" 

J W I | | 

VK9JK. 

VS6DO, 



stations: 

KF4SJ, 

VK9XX, 

VS6DR, 




MCAS IWAKUNI, Japan, Oct. 
5 — Captain James W. Jackson is a 
quiet man, bur his voice has been 
heard all over the world. The 32-year- 
old native of Rochester, N.Y-, oper- 
ates KA5JJ. the only authorized ama- 
teur radio station here. Captain Jack* 



14 



91 



'J9PZ0 hn 'rifrnv 

'■w-V/i' Ph w g 01 sjummiioj moA pua$ 

s?9tt:o HU fo*&'*tf ft xbfi 

uofjuauE pilC 3UJ() 
jnoX joj qnrHU Xj^a no a >|uni[x 

*orpcJ tueq dji? jnqj r>[do?d «"Mfj 
jo ainioid [fejdAd un jo3 tu adoq J uou 
-nuuojui jiioa vfrxfti ;siueq irtbqe apnea 
aq ut?,i uotjivqiMnuoS jn,\iS iuo ou 

] IT IJ I UUffUOD OJ 0U!L[ IJ3A3 A1HU J 'JSEJ 
LIj ' ipjFVOJ ALU tlf ^pTTLLl ^APlj | JRqj 
SUOIlt?Z![Ri^LI^S ,>L[J JO 3IUOS ULtyUGO 
03 3doij I UOI}BJddOOd JUOA l|JJ^ 

ninp a'iu joj jurjjodiui aj^a 
si sii[j x\va[ noX 3SU93I] jnip\ pun 
umq it r \MioA j;u[pi|A\ ajnjs noX jnqj 
.tjuav noX j] imp sjns aq jsnpssajppe 

JilO A OIL! ;iA|B JO ,1UIRLI JnoX IJ^IS 

o) po.TLi ] nop no a 10EJ u\ mjij j^pio 

[fCIU IT JOJ S3LUEU J MOA l^fy O] KLIjAJJ 
>|00*| JO UITLUsOp^ 3U105 IQU IUJ (£) 

pun K>uopyuoo is^ijjs ^qi hi ppq 
dq iijav s,>iupu jtioX (£) pun *~[}{}j y 
m[4 jo [BAOjddc ^i]i i[i(A\ qaiEds 
-&i ^pij Btioq 3uiop jsiSojodojinun 
?uiiftia3 n tun \ \ j \ iRtfi noX amssn ] 

■oipRj ujiu[ jo joafqns 9sg lio 

jnoqn ^jnj oj m\\\ p noX jrcqj jo ^Liii[i 
un3 noX SimtyUB inoqn dUl [pj ivnf 
£$R83 jo ^urqi noX op mm £S3uo 
ipiqw " " " qnp " " ' jau i? oj 8uo[Dq 

HO A 0{J <spilEq 3JUOABJ JUOX Ajn 3IU|A\ 

t jt .^r.iu jo JBaS Xnq noX qq t ".t>ipnj 
uinq til asdq noX ttcq ouo| avojj tit > k )j 
• ll l± <. l>l>IV ^[1J ( » 3Ji»qi no a op ]i?q ; \\ 
*ojo WV jnoqc [MJ noX a\oij j-\X0 
B =U t nbX n jo \\\ ^hsS \\\ ) l"*>qr 
psj no\ t>p .woq uinu ^uoqd e 3J no \ 
j[ juoukiinbA iiu>\ jnoi|n otu \pj^ 
suinq A\o[pj JtioX jo ^uiqi noX jtujav 
l a5[ij ,iq pinoqs uipq [Eapt m\i yu\m 
noX u?ijM % ('3& "sj^u '\\j 'suoqd 

'SllfXCl) °!P^ J U,l -M u ! t ^!A^ 1^-H| op oj 
05ji| noX jni|A\ ^^jji s8iiii[i oiu [pi ud 
uo\ oiptrj Lueq Xqqoq jno\ inoqi? 

.■UU ||^ij pUiT Jd)J^[ t! AUI pjuav isnf 
"JJO ptlllOS 0\ K>UEI|0 JnOA SI 0.iO|[ 

-dpq iitoX p^^u j "sm?n[ aip si 
u iiti[a\ oipnj tunq .^>(Fnu oija\ qdoad 
.n|] ojui MjSfsu! (Ajmnurmoo pur 
3fi9[(03 ipoq) 3t[qnd ^t[j ^^piAOjd oi 
m [eoS a^\ t sis^m jotu^s Xui joj oipcj 

LUCl| IF >|00| IE^lS0I0d0Jl[lUFT UF! Em 

-yv,) js[ifojotiuJi|iun ju^pms it heb [ 

03±NVAA d!3H 



HI- \\ 03WKM0JJ \JJt?[| 

"uosr.^j attxes 

(5l[J JOJ 5JR[ Willis ^l|| J^jJHS p|ITOA\ 

itui jo paiuaied ^poo .^joj^ pasiASj 

r- jiH[} aits oi ainiu^A I pun *^fjjo 
juaicd m[\ jo sp|ij jilj i ut jsnp iluua 

-IJlirt? SI tJOfillAAUl STljl Al|A\ ]T1U SITLSiJ 

oi jqSnom qnnui ^Jinbsj j us^op i| 

■j i SajXeid 

si:a\ isiunfd ,n|j X^>( jih|a\ jo ss,^[ 
-pjl^OJ pn/i[unpuii]s sem ^uu^Suy jo 
Ijo drjs oj sjaSuij jijj joj S3J0U >pqq 
°M 'Ajpifdnijj jo aunr ,>qi sbm it*qi 
sl|i?i pajdt) jo luoisXs r qjiM pattoq 
-X^>| QiiEtd p p^iuoiRd pun podopA^p 
sniuaS [BDisnui n o3n sji^X ^mog 



7 UP J JM "\ 

„ini|] upqi 

jjq op unn noX 'sXnn no aiuo >„ X[d 

-dns AOrf ^js^q l^o S|ioi{S Hitnuiituui 

oj j^s jj - jod ^|ooi - ^lini ^n^u 

IO[f\\ fq % /lddns J3*oj ^fqnun A „ 



4(| ,i] ? M? ;) m^hj 

\HdeVft »'»jj,tSp3 uqof 

rsj^a &D|A pun -^ -Si^ jopun 
ncj pjnoLjs 3 jnpun uoEjdna osjy -itsjoa 
a»DlA pun g -8y j^pun ^q ppioqs | 2\ : \ 
j ^ pun uoijdt*n -£ j -q^j K | O'l ^ §Rd 

SNOIlVOIdHdlAIV 

aisjv SNOiioaaaoo 



SdptS lfj</q UOptm <?q oj }Of v \i 

-uvqj JdWdddu p.wpunjs SuiztuoJtfDU/Cs 
tnoqp ]$&£ ajdfhid .hii{jt> up MOfj 
3S wq«in|cr) 
SftStA \\^ ,M S'\ * ,,,? A 

'^joa\ pooS rll|| dll d^A>j 

*sui3;s Jt^ieod^j pj^pi stops o[qn 
-|;t!ap ^}|cui X|qnAt»uo^ ppioo ji ^os[\ 
■ofpej Jiipjnuit? jo snjeis ^qj SAOtdttij 
d|Aij p[no.T su[j jnq 's^puonbatj os3t[j 
oi p^uyuo.t ^q oj j^a^u rxloq oeo 

P A\ "sapH^nbay SHJVy p^zuoqpra 
^i|l qiiM soi^u^nb^jj puui*i[.i ssoqj 
ip^ntu oj ,H| ppioM jopisuor* iljSiui 
noX 9S[a 3iiji|i^uios >jonj| jt|Su ,">i|i UO 
^jn no a |35j | "sAL^u^nbajj Jd)?dddJ ^ui 
-Ui^ouoo [BuojipamoX pj pmooj u| 

S3l0N3nO3ad S33VU 



'StiftuiWi tsvd ft* UiOpSfM 

aifi tj/iM (}<:£ pun ()-- iwfd s jjj , i/ut 

spfi ji Op &m p/noM "wvSv jjjo up 

op oj ji pinf &m j'f fwjiAKi *>w Supvds 

jndjno piw jndui uo motUfdo J^ifJQ 

dih| iLKi \ 

a}B| ooj si j[ p\ioj.^q mou p.^jnih 
-.u si uofinurpjoon Xouanbajj ^mog 

■fui^nds t^sop g i|iiA\ x^fdup ^pqoiu 
^jnj^do ^M ji made [jiaa sjajnodoj q^iM 
mou SUTABq ,^jrr ^a\ mi^jqojd ,isiou 
pun ^uisu^^p ,-nur\ ?i\± \Xea\ iqStJ 
oqi x^|Unp uo jobs i,^ /|HM £ ^q P^) 
-EJEdos spuupqo oa\i i|j|A\ j£g] inoqn' 
X|Uo pdddojp j^Mod luusucj) dq) inijj 
punoj juin (^-.)| un p^jerqcAd | ajju.^ 

-0>| 9|qtSSOd Sj ^niU!J 7}flfl l R J^AO 

j^UjtiiMinji n SutjEiOdo os SJay[[dtUtf 
punqpnojq oi A\ot| 8u;ujnd] aiB sjajuj 
onjnuntu A|iqoiu ^i\\ si jsavsub jujx 
os|n X3{dUtt5 Ainj.xlo o) jurm noX |j 
l^aJS i >oj si pn.\ids oqi i iti|4 lu^umSjn 



L 



•uotjnj^do oipnj jgrqmiie 
uo S9SSE[.^ pajrmpuo:* ^q b PJ.">i|i SBM 
3t| 3(P|M uinup! ; \ jo Dfiqnd^y ai|j 

uj >(Jomj^u S^VIM ^ l il d' 1 }^ s °4 ^ u ! 
-dpq qjiM paijpai;' st ut^s5)3nf idi?^ 

-Suq ut uoiieuuoiui iLun.iodnu j.nrjo 

pun 3UJEU 4 UOt|SDO| "UlSls ||E3 JK^qi SAlS 
oi A\oq A\ou>j p|JOM sip inoqgnojqi 

sjnojnum iso|^^ skirls ^q au^iqojd 

p. jo tpnui jcqj ion s; 3j?Btt3uB7 r , 

"SO °M l uiqiiM paildjsUBI] si ^q 
tuqM tuiq mm luaiudmba aqi saAoiu 
uos>|ARf 'sjphijo XurttJ puE *uap3A\s 
A^unjj *a|iLL) 'BUiqj 'Eissiiy sn 
s^tJjunoa q^ns oj opo.i pun 3oioa qioq 
sjsEOpEQjq ^i[ qarqM luojj *sn at B 
uj sumo ,n[ uounjs n oiuj ^uoS 9ABq 
000" ^S A|je^»u pun sjesX Xjuoavx 

uoissiitiiuo isuoijn.^ 
-juiuiuuo ) i ir.iopo | jj[j oip Xq pdnssi 
*SdSU3Dj| uorjnjs pun JojEJsdo SSBp 
pn^URApn S 4 UOS5pEf idnj jo siscq ^qj 

uo psjtiEjS sum i| "SVJW J° Jtl ^LU° 
Sujpunuiiuo^ ^q] pun *uEdcf saoioj 
[BAEfs| 'S'fl japuBunuoo aqj ipnojqj 
*undnf ut ss^joj §[\ jo J^pununuoo 
^L|l Xq pajUEJg sra\ tun^EMi SVJIAJ 
f^jnoqn 3XEJ»do oj uoiss|iuj,i c [ 

jt >;n oj 
(OU S9SOOqo tios^nnf idnj 'Xjiijqndno 
aotOA seq j i t[Snoqj[y apoo 3SJO{\ 
jnuoi jbujoju i ipcojq '( S M W V » 

Lioijf?)s oipny .\jeji[]Jv Xjnifixny 
un pautell Xjini.Tijjo 'uopms r»i[j 
•siu^ji ^pRtu^uioq auios pun *s33jaj?s 
[tpads SVJt\ llloJ J ^J^ ! Ajnjodiusj 
uo jurnuduibA qi|A\ p,>iRJ,ido si ffgy^J 
jnqi p^umjdx^ *%u\\\ ijnj^Jty 3UUEJV 

i s I l(SHA\l\) uojpnnbs sj^jjnnb 
-pn^u 3uiyv\ ^ttun^ oi p^u^issn *uos 



Aqj qjiM dn .^uio^ Xeuj ^uo^ujo^ 

BULinds mvi p ^ n J° u ^M* os peaicb 

Z HW $ r SVA \ OCT P on Supnds 7 II ul 
g*£ nKn jou XqA\ os pnr>Jds /j|j\ ^ n 

vnij punq j^joui OM^ aqj_ ^uoijnnqddE 

suoqd^pj joj ui m \ £ \ ^ a]uo satn 

jtolu J3xqdnp u smODjsAS^ ^fiqoiti 

Aqi spistn jipiJ itj oj ipius X|,iuj^jjxp 

Siaxd[diip ^jiqoui ^SffMJJ oj .i[qivsod 

si i[ sSubj zhw 0S1 ^ l H "! 2|iw y;*S 
jo peaids Xou?nhpjj n i|jia\ \^|dnp 
A|iqmu s3jnj T xlo XuEduioo ^uoqd pqx 
'X^fdnp X[p\| oS ^a\ u^t|A\ \ij dturv 

-n[J 05111 S^ApSJnO JAB ){)U s^pt 

^sjnxo|dnp jmn s.iijiAn^ 1[j;m 
pdAjOAtn jso^ pun sui^jqojd jo uou.^iuj 

E SI l^Vi | JE p^JAJUIlQTU^ SUI^I 

-qojd .ill] *3u[.inds /(([^ g- X[UO qjlAS 
sj.^ji:.idai jpqj Stni&iddo Xq ^^njsitu 
iiq n dpeui sjnajnum sqj jnqj noX 
qjtA\ 53j3n X[pij j f i jo anssi n ur.f 

tJ| [RLLOJJpO JlloX IS3J34U1 L[JIM pe^J 1 



» : . j;I noX q.eq^ ^sjsuf j 



K * 




3SUOIAI Q3SIA3H 



Xr<: 



■ 



t uop suooS no 



♦.♦-♦:♦:♦:♦:♦:♦:♦:♦:♦:♦:♦ 



Caveat Emptor? 



#:♦:♦:#:♦:♦:♦:♦:♦:♦:♦;♦.♦ 



Price - $2 per 25 words for non commercial 
ads, $10 per 25 words lor business ventures No 
display ads or agency discount Include your 
check with ordef. 

Deadline for ads is the 1st of rhe month two 
months Qfior to publication For example 
January 1st is the deadline for the March issue 
which will be mailed on the 10th of February, 

Type copy. Phrase and punctuate exactly as 
you wish it to appear Mo all-capital ads. 

We will be the judge of suitability of ads Our 

responsibility for errors extends only to print 
mg a correct ad m a later issue 

For $1 extra we can maintain a reply bote for 
you. 

We cannot check into each advertiser, so Caveat 
Emptor 



HALLICRAFTERS SX-115 Receiver, 

Johnson 275 w Makhbox/Swr. John- 
son TR switch. Kniyhl TlSO, PH 
Linear LA400c. Hud Johnson 
K I I1GK. 4X New Searles Rd.. Nashua, 
N.H. 03060. 



GREATER BALTIMORE HAMBOR- 
EE. Sunday April '> at 10 A.M. Calvert 
Hall College, Goucher Blvd. and La* 
Salic Road. Towson, Maryland 2 I 204. 
(I mile south of Lxit 2X Beltway- 
Interstate d95> Food Service. Prizes, 
Flea Market. SI. 50 Admission, NO 
TABLE CHA&GE OR PERCENT- 
AGE. 



BUY OR BORROW lor copy Tech. 
Manual lor Corps of Engineers. 5kw. 
Engine Generator Unit, Hollingsworth 
Model EA-536, Stock List No. SNL 
17-1780. 525-25. Will pa> premium. 
W5BOY. 365 W. Saxet Drive. Corpus 
ChristL Texas 7840S 



WANTED - Bird Model 43 
wattmeter elements: 100 250 MHz 
one 5 watt and two 25 watt. 
200 500 MHz one 10 watt. State 
condition and price. Technical 
Editor, 73 Magazine, Peterborough 
Nil 03458, 

WANTED Tektronix Model 53/54C 
or Model (A or M scope plug-in. State 
condition and price. Technical Editor. 
73 Mae.a/ine. Peterborough NH 
03458. 



TECH MANUALS So. 50 each: 
R - 3 8 8 / U R R . R - 3 8 9 U R R . 
R-220 URR. SP-oOOJX. URM-25D. 
B C - 6 3 9 A , TS-497B/URR, 

TS-34A/AP, OS-HE, U, BC-348JNQ, 
BC-779H. CV-591A/URR. L.M-21. 
R-274/FRR. S. Consalvo. 4^05 
Roanne Drive. Washington. DC 
2002 1 . 



WANT CLEAN COLLINS 51J-4 . also 
Drake C-4. with manuals and original 
shipping containers. No junk! First 
letter give each serial number, condi- 
tion, price; also price for both, it' have 
both. Watson. 700 West Willow Street. 
Long Beach, C A. 90806. 

GONSET COMM. IV 6M. factory 
closeouts*' with P.T.T. mike, AC, DC" 
cords. Lasi uii'S Gonset will nnike. 
Only S 1 6 1 > . Gam inn nica tions 
World, Inc., 4 State Road, Cleve- 
land, Ohio 44 1 09, 

SWAN 260 XCVR WITH MIC f ac/de 
supply, mobile ant. mobile mount 
4btv vertical. I5mtr beam S350 (603) 
524-07 1 6. 

FOR SALE: Galaxy Station GT550 
with accessories SC550, AC400. 
CAL-25, F3 CW filter, VOX35< 
$450.1)0. Fine condition. John 
Ivanisko, 5 Clover St., Yonkers, N.Y. 
10703. 

EVANSVILLE, Indiana HAMFfcST 
-111 Grounds (Highway 41 \orlh > 
miles) Sunday, May 7, 1^72; air con- 
ditioned, auction, overnight camping, 
ladies* bingo, reserved Ilea market 
booths. Advance Registration. For 
flyer, contact Morton Silverman 
W9GJ, 1121 Bonnie View l)ri\e. 
Evansville, hid. 4771 5. 

ROCHESTER, N.Y, is again HamfesC 
VHF meet and Ilea market headquar- 
ters lor the largest event in the north- 
east, Maj 1 3 1 h . Write WNY Manifest, 
Box 1388, Rochester. N.Y. 
14603, 

HAMF EST WABASH COUNTY Ama- 
teur Radio Club's fourth Annual 
Hamfest Sunday, May 21. Rain or 
shine. Admission is still only Si. Flea 

Market - no setup charge, tech. talks, 
bingo for XYLY and much more. For 
more in formation write to Bob 
Mitting, 663 N. Spring St.. Wabash, 
Indiana 46 c »2. 

MOULTRIE AMATEUR RADIO 
KLUB, 11 th annual Manifest, Wyman 
Park, Sullivan, Illinois - April 30, 
1972, Indoornujtdoor market. Ticket 
donation S1.00 in advance - 51 .50 at 
the gate. Open 8:30 A.M. W*>BIL 
146*94mhz, M.A.R.K. Ine . P.O. Box 
327, Mattoon, Illinois 61938, 

21ST ANNUAL DAYTON Hamven- 
tion will be held on April 22, 1 972 at 
Wamplers Dayton Hara Arena. Techni- 
cal sessions. Exhibits, Hidden Trans- 
mitter hunt, Flea market and special 
program for Hie XYL, For informa- 
tion write Dayton Hamvention, Dept. 
S. Box 44, Davtoii. Ohio 45401 . 



2-METER FM INOUE IC-10, Brand 

New, I &. K» wans, solid state, 12 
channel, w / K t a 1 s, w /accessories, 
2 3 5.00, Bob Brunkow 
206-747-8421, 15112 S.E, 44ih Belle- 
vue. Washington ^8006. 



FCC "TESTS-ANSWERS" . ., 
Original exam manual for First and 

Second Class License, plus- "Self- 
Study Ability Test" Proven! $9.95. 
Satis! action Guaranteed. Command, 
Box 2h34K-S. San Francisco c )4 1 26, 

WARREN ARA'S FAMOUS HAM- 
FEST, now family style, Aug. 20, 
Yankee Lake, Ohio, Gigantic flea mar- 
ket, swimming, picnicking, play- 
ground, all free. Camping available. 
Details: QS LWSVTD. 

WANTED Motorola I 1020 A fre- 
quency deviation meter state age. 
condition and price. Technical Hditor, 
73 Magazine. Peterborough. N.H. 
0345& 

RUN SAWS, DRILLS. LIGHTS and 
many other items from 1 2v to 1 20v 

Auto Meclric Power Converter. Hook 
to your car or truck alternator, lias 2 
outlets and voltmeter. All instruc- 
tions. 3% x 8 \ 2 l i metal case. Send 
$14.95 plus SI. 00 handling to: Phil 
Bowers Associates. 71 Beechwoou 
Wakarusa, lnd.4o573. 

BUYING? SELLING? TRADING? 

Don't make a move until you've seen 
our new publication, free Sample 
copy! Six issues SI. HAM ADS. P.O. 
BOX 46-653P, L.A,. Cal. 90046. 

HEATHKIT HX 10 MARAUDER SSB 
transmitter, professionally wired, no 
mods, mint condition. ' SI 50.00. 
WASSYC Hcnr\ Parise; ISM Lexing- 
ton NAY Warren. Ohio 44485, Ph. 
216-395-4938 

EXHIBITORS Reserve space now 
for ARRL Hudson Division Conven- 
tion. Oct. 21-22. Tarrytown, N.Y. 
Contact Hank Frankel. WB2DQP, Box 
35, Bellmore. N.Y., 1171 I. Phone 
212 394-5257. 

ALUMINUM ANTENNA MASTS, W 
lon» x 3" dia.. x 3W dia. at base 
(sleeve 6" long over end), Painted 
green. 20 lbs. Unused. Very heavy 
duty. Can be telescoped with short 
insert. Ideal for Field Day, Pickup 
preferred. $9,75 each. K3MNJ, 8361 
Ungdon St., Philu., Pa. 19152. Tel: 
215-RA5-2373. 

NEED OLD ISSUES or copies of 
A.T.V, Experimenters, A 5 Magazine 
or any magazines on A.T.V. State 
price 1st letter. Gerald Cromer 
K4 NHN. 1014 Summerland Dr., 
CayecS.C. 29033. 

14AVQ VERTICAL, nearly new - 
25.00; Hornet 3 element tribander 
with manual, fair condition, recently 
dismantled $25.00; both 
S40.00 ,WA4TST, 507 Pinecone, 
Waycross, Ga., 3 1 50 1 . 

FOR SALE: Back issues 73. I962, 
I963, I964, 1 965, I966 and laien 
Send SASE for list, Ray Helmick. 
1 423 Spring, Parkershurg/WV 2610] 

HEATH SB 200, extra set of finals 
SD0 or trade for 2mtr FM mobile. 
Swan 240, AC power $70. Will ship. 
R. Lloyd. 705 B Whiting Ave.. 
Albany, Ga. 31701 . 



16 



Jack Townsend W4RIZ 
124 S. Douglas 
Wilson NC 27893 



Power Amplifiers for Two Meter FM 



A simple and compact power amplifier 
to boost transceiver output 



With the increased popularity of 2m 
FM has come an increased need 
for additional power to boost the range of 
surplus FM transceivers. This amplifier is 
designed for such service and operates with 
only 5 W of drive to produce outputs in the 
order of 200W. 

Simplicity is the keynote in the design 
and construction, it uses no silver plate, no 
neutralization, no bias supply, no screen 
supply, no grid loading, no plate loading 
capacitor, and suffers 'no damage if drive is 
lost. In addition, there is no necessity for 
protection of the tube in case plate voltage 



is lost since screen and plate voltages are 
provided from a common supply. 

The amplifier derives all operating volt- 
ages from the plate supply and plate 
potentials may be used ranging from 750 
to 1600, The most efficient operation, 
however, lies in the region between 1300 
and 1000, Screen voltage is dropped from 
the plate voltage by five resistors totaling 
50 kO. Five zener diodes stabilize the 
screen voltage and do not allow it to 
exceed 310V. Any combination of zeners 
may be used. The 62V I0W zeners used 
here were chosen because of their avail- 







Grid input is at lower left, plate output at upper right. BNC connector at lower right connects to plate 
supply , switch on right changes screen voltage. Filament transformer on left is tapped to allow 
adjustment of filament voltage, 



APRIL 1972 



17 



INPUT S LI r 
DRIVE S22 ^ 



20 pF 



L2 



■ 


PART OF SK-600 SOCKET. 


C9 f Cl0 


CENTRALAB B5Ba-100Q. 


CH 


NEUTRALIZING CAR 1-3/4 in DtA, 


Dl^t)6 


62V, 10 W ZENER, 


LI 


2T 18 AWG TINNED l/E m DIA, 


L2 


2T 8 AWG BARE 1-1/4 in 01 A 




SPACED 1 in. 


RFCI 


30 T 20 AWG EN AM 1/4 in DIA. 


RFC2 


SOT 20 AWG ENAM 1/4 m, DlA, 


Tl 


12V FfL XFMR TAPPED AT 




5.4 t 5.7, 6.0, 6.3 B 6.6 VOLTS- 



4CX250B 




■ 5 P F V 

600V 
DISK 




[400 <400 
IOW ?K)W 



mAJO-500 



mA}0-20 



Tl 



NC 




£ 



y ^' ^ ^i 



f 

X 



JUMPER 

j * 

6 7 6 5 4 3 2 1 

t_t 




OJOUTPUT 



JUMPER 



m 

VAC 





BNC 
+I500V 




BLOWER- 20 CFM 
OR BETTER 



Fig, I. Schematic of high-power rf amplifier. Cj-Cg- 600V Disk; C 9 , C ]Q - Centralab 8585-1000; 
C s — part of SK-600 socket; Cj| — neutralizing capacitor 133 in. diameter; £>| — Dg — 62 V 101V zenen 



ability on surplus at two for a dollar (Delta 
Electronics, Lynn, Mass.). 

A single-pole double-throw switch 
changes screen voltage from 310 to 
124V, allowing reduced input for tuneup or 
local work. Those interested in a greater 
range of power control may install a 
four-position rotary switch to tap into the 
zener string at each junction. All dropping 
resistors and zeners are located below the 
chassis directly in the air stream from the 
blower. 

■ 

If zeners are not available, two VR-150 
gaseous regulator tubes may be used, but 
the chassis will have to be made larger to 
accommodate the sockets. 

If it is desired to monitor screen voltage 
and current, an octal socket is mounted 
behind the filament transformer. The jum- 
per may be removed from pins 1 and 2 and 
a milliam meter inserted to check screen 
current during operation. If screen voltage 
readings are desired, the jumper is left in 



place and a voltmeter clipped to the 
jumper and to ground. If there is any 
doubt regarding the screen dissipation, it is 
suggested that the manufacturer's specifica- 
tions be consulted. 

Because of this system of deriving 
screen voltage, an external screen supply is 
not needed, The price paid for this benefit 
is the use of zeners and dropping resistors, 
but mounting them under the chassis tucks 
them away neatly and the blower keeps 
them cook 

Control grid bias is supplied by the drive 
in a conventional manner and protective 
bias is developed across a 20012 cathode 
resistor shunted by another 62V IOW 
zener. In this manner the cathode bias 
protects the lube and provides a minimum 
voltage at all times, while the zener clamps 
an upper limit of 62V on the bias, allowing 
the tube to handle more power at high 
current, A zener may be used in the 
cathode lead without the resistors, but it 



18 



73 MAGAZINE 




Bottom view of amplifier with cover removed, Zener regulators on copper heatsink area are at lower 
right, screeen dropping resistors, bias and' cathode resistors at upper right located in at stream of 
blower for better cooling. 



operates too close to maximum ratings for 
good design. 

Manufacturers reeomend a screen volt- 
age of 250V on the screen of the 4CX250 
while this dropping network places 310V 
on the screen instead. When calculating 
screen dissipation he sure to take into 
consideration the fact that the cathode is 
at 62V above ground, making the actual 
screen voltage 250 with respect to the 
cathode. 

Filament voltage is provided by a 12V 
5 A transformer tapped on five consecutive 
turns. Specifications call for 6.0V on the 
filament of the tube and it may be desired 
to adjust this voltage to compensate for 
variations in line voltage and tube aging. 

To tap into the windings, remove the 
shell and outer layers of insulation, ex- 
posing the heavy turns of the secondary 
windings. Plug the transformer primary 
into 115V and measure the voltage on each 
exposed turn by clipping an ac voltmeter 
to a razor blade and gently pressing it into 
the enamel insulation of each turn, The 

FLATTEN, DRILL B BEND 



3/8 in. DIA 
SUPPLY PtPE 



turns to be located are those which show a 
potential of 5A f 5.7, 6,0 ? 6.3, and 6.6V. 
Most transformers are wound for three 
turns per volt, so these turns will lie side by 
side. 

Tap into each of these turns with a 
flexible lead which will later be brought 
out of the transformer- Pry each turn away 
from the body of the transformer with the 
point of a small screwdriver. Cut the wire 
and solder a small loop of bus wire to the 
ends and solder the flexible lead to the 
terminal thus formed. Insulate the loop 
with a strip of cardboard before pressing 
back into place, A coating of corona dope 
or shellac completes the job. 

The five new wires are brought out of 
the transformer to the octal socket behind 
the filament transformer and terminated 
on pins 4 ? 5, 6, 7, and 8. Pin 3 feeds the 
filament current to the tube, so a jumper 
from this pin to the appropriate pin pro- 
vides the proper voltage to the tube. It also 
allows the operator to monitor the fila- 
ment voltage when desired by clipping an 




6 fn. 




.00 1 f 5 kV 
DOORKNOB" CAP 



SHIM STOCK 
STRAP 
I in. x 1/2 in. 



Fig. 2, Detail of plate inductor. 



APRIL 1972 



19 




Top view of amplifier showing plate assembly and sliding tap on left Tuning capacitor is neutralizing 
type made by National Below filament transformer on right octal socket allows adjustment of 
filament voltage and metering of screen current. 



ae voltmeter from ground to the jumper. 
Monitoring filament V voltage on the 
4CX250 is normally difficult due to the 
closed and pressurized grid compartment. 
The plate circuit is quite simple and is 
capable of efficiencies of belter than 60%. 
The plate inductor is formed from a length 
of "supply line," a chrome-plated brass 



tube used by plumbers, available at hard- 
ware stores for about 75</. The ends are 
flattened and formed as shown into a 6 in, 
length. The cold end is fastened to the 
chassis while the other end is attached to 
the plate coupling capacitor and the stator 
of the plate tuning capacitor. The other 
terminal of the coupling capacitor is 



2-1/4 in 



FUSE 
CLIP 




BEARING FOR 
ROTOR 



1/4 in. COPPER 
STRAP 




4-1/8 irv 



H 1^7/8 in; 



W 




HOLE FOR SK-600 
SOCKET a 5K-606 
CHIMNEY 



5 in 



JO in 



Fig. 3. Detail of chassis. 



20 



73 MAGAZINE 




N 



/ 




* 



4 






i 




m 




Tube and plate assembly showing coupling capacitor and bypass at lower right Coupling capacitor is 
held to tube by a copper collar and short strip of brass shim stock, Plate line is a length of chrome 
plated supply pipe. 



screwed to a small strip of shim stock 
which is clamped under a copper collar 
encircling the tube. The copper collar is 
held in place with a brass machine screw. 

The plate tuning capacitor is made from 
a National neutralizing capacitor with 
plates \% in. diameter; the movable plate is 
supported by the original bracket bolted to 
the front panel. The shaft extends through 
the panel far enough to accommodate a 
plastic knob. Place a small compression 
spring and a washer between the knob and 
the panel to spring-load the capacitor, since 
vibration would otherwise cause it to 
creep. 

If a neutralizing capacitor is not avail- 
able, one can be made from disks of copper 
or brass soldered to a 0.25 in, brass 
machine bolt. In this case the shaft will 
work into a brass or copper plate screwed 
to the front panel. Again, don't forget the 
compression spring. 

The only store-bought components in 
the plate structure are the two high-volt- 
age, high-frequency capacitors (Centralab 
858S-IQ00) used for coupling and by- 



passing and the tube socket and chimney 
(Eimac SK-600 and SK-606). The chimney 
is necessary to force air ill rough the plate 
efficiently. 

The plate choke is formed of 50 turns 
of 20-gage tinned solid hookup wire with 
the insulation removed, wound around a 
0.25 in, stove bolt. When the bolt is 
removed the turns will hold proper spacing 
and can be wired directly into the circuit. 

The loading assembly consists of a brass 
fuse clip chosen to fit snugly on the plate 
inductor, to which is soldered a copper 
strip 0.25 in. wide and long enough to 
reach the output connector. Loading is 
accomplished by sliding the clip on the 
plate inductor. 

The amplifier is constructed on two 
chassis, the lower one 5 x 13 x 13 and the 
upper 5 x 3 x 10 (Bud AC-404 and 
AC-422) fitted with an aluminum plate on 
the bottom and a perforated aluminum 
plate on top to permit air to escape. The 
two chassis are bolted together with eight 
brass screws and the tube socket hole cut 
through both at once. It will not be 



APRIL 1972 



21 






Plate assembly and stator of tuning capacitor. Plate choke is wound from 20-gage bare hookup wire. 
Brass fuse clip below slides on plate line to adjust loading. Quarter inch copper strap connects fuse clip 
to output connector. 



necessary to make the grid compartment 
air-tight if the large blower is used. The 
blower provides enough air for both com- 
ponents and tube. In order to assure 
sufficient flow some small holes should be 
left in the lower chassis, Leave the holes 
open in the corners of the chassis as 



octal socket and at the filament transfor- 
mer with putty or plastic tape, 

Parts placement is not critical. Keep 
components in the lower compartment 
away from the grid coil which is supported 
by the tube socket on one end and the grid 
tuning capacitor on the other. The grid 




Grid assembly of 8-gage bare copper showing tap to grid choke. Choke fastened to 10 kfi grid leak. 
Mechanical rigidity is aided by fastening one end of grid coil to tube socket and other end to tuning 
capacitor. Zener regulators are partially visible in lower right. 



22 



73 MAGAZINE 






plate choke, but with only 30 turns. It is 
necessary to use dissimilar chokes to avoid 
possible oscillation at the resonant fre- 
quency of the chokes. Bypassing of the 
cathode is accomplished by soldering in 
two disk capacitors at each of the four 
cathode terminals. It is not necessary to 
bypass the screen since this is done inside 
the socket itself, 

Plate-voltage connections are made 
through a BNC connector. These connec- 
tors seem small and subject to arc-over but 
in practice operate well up to 2000V and 
are readily available on surplus, A jumper 
of RG-58/U coaxial cable equipped with 
male BNC connectors may be used from 
the amplifer to the power supply. This also 
provides a ground connection along with 
the high-voltage connection for greater 
safety. Even with this method, an added 
precaution would be to run another ground 
from amplifier to power supply separate 
from the one above. 

To place the amplifier in operation put 
both top and bottom covers in place and 
energize filament and blower. Connect a 
wattmeter and dummy load to the output 
connector and a low-power 2m transceiver 
to the grid connector. Activate the trans- 
ceiver and tune the grid to resonance 
indicated by a reading of 5—20 mA on the 
grid meter. At the same time the cathode 
current will indicate since the same current 
flows through this meter but the indication 
will be small. 

If the drive is satisfactory, place the 
screen switch on "low'* and apply plate 
voltage, Plate current will rise to about 60 
mA. Tune plate for maximum indication 
on wattmeter. Some mechanical adjust- 
ment may be necessary between the rotor 
and stator of the plate capacitor. Loosen 
the collar around the tube and shift the 



READ THIS BY "GUS" W4BPD 

(Actually an advertisement in "disguise") YOU 
spend hundreds of $ on gear, antennas, mikes, etc, 
then YOU spend countless hours of listening & 
HOPING for some DX. WHY NOT do it the easy 
way ? Subscribe to the WORLDS ONLY weekly 
DX Magazine and do it THE EASY WAY. DX news 
in depth, upcoming events, dates, freqs, times, DX 
QSL info, stories & articles by DXers, pictures, ALL 
you want to know ABOUT DX ! NOTHING ELSE! 
OH YES - I also print FB QSL r s, priced right send 
25 t for 25 samples and price list. How about it ? 
SUBSCRIPTION RATES: First Class Mail to USA, 
Canada & Mexico 6 mo, $ 6.00 or 1 yr $ 12.00 
THE DXERS MAGAZINE, DRAWER "DX", 
CORDOVA, SX. 29039 -U.S.A. (THANKS) 



position of the shim strip to place the 
stator in a better position relative to the 
rotor, Form the habit of always turning off 
plate voltage before removing the top 
cover. 

If the plate tunes as it should, adjust the 
loading clip by inserting a tuning wand 
through the perforations and shifting its 
position until an optimum position is 
found which produces maximum output. 
Retune the plate after each change. In the 
dmplifier pictured the optimum position 
was found to be 0,75 in* from the cold 
end. 

At this point you should, with about 
1 600V on the plate, see about 40W on the 
wattmeter. Change the screen from low to 
high and retune the plate. It may be 
necessary to shift the loading clip slightly 
on high power, Plate current should now 
stand at 180 to 220 mA and output power 
should increase to about 200W. Turn off 
the amplifier and replace the dummy load 
with the antenna, again optimizing the 
tuning. The tube runs warm under these 
conditions and if a hand is held over the 
tube hot air may be felt exhausting from 
the tube. 

To calculate plate input and efficiency, 
allowances must be made for the cathode 
bias. If 1600V is used on the plate, the 
actual plate voltage will be 1 540* If 200 
mA is indicated on the plate meter, grid 
bias must be deducted, 10 mA grid current 
would have to be deducted from the 200 
to give a plate current and screen current 
(combined) of 190 mA. If measured screen 
current of 20 mA is deducted from the 190 
mA, then the actual plate current is 170 
mA, Thus, the adjusted plate current must 
be multiplied by the adjusted plate voltage 
to arrive at the actual input power of the 
tube. 

If trouble is encountered at any step, 
check wiring, components (even new com- 
ponents are sometimes defective), solder 
joints, and the tube. It would be wise to 
obtain a used 4CX250 or 4X1 50 A for 
tuneup purposes, Many FM and TV trans- 
mitters retire these tubes when emission 
drops. It would be better to use an old one 
for tuneup after which a good tube can be 
substituted for full power. .W4RIZ 



APRIL 1972 



23 



UP 

Professionally Engineered Antenna Systems 





Single transmission line "TRI-BAND ! ARRAY 



J* 



By the only test that means anything . . , 
on the air comparison . , . this array con- 
tinues to outperform all competition . . , 
and has for two decades. Here's why 
. . , Telrex uses a unique trap design 
employing 20 HiQ 7500V ceramic con- 
densers per antenna. Telrex uses 3 opti- 
mum-spaced, optimum-tuned reflectors 
to provide maximum gain and true F/B 
Tri-band performance. 

ONLY TELREX GIVES YOU ALL 
THESE FEATURES... 

• Power rating 4 KW PEP . . . 
rain or shine 

• Wind rating survival 110 MPH 

• Patented broad-band coaxial Balun 

■ Heavy-duty stee! gusset mounting 
plate 

■ Aluminum boom 2 in., 2Vz in, O.D. 
x 18 ft. 

• Large diameter, .058 wall taper- 
swaged dural elements for minimum 



weight and exceptional strength 
to weight ratio 
• Stainless steel electrical hardware 

With a Telrex Tri-band Array you get 49 
lbs, of educated aluminum engineered 
and built to provide many, many years 
of performance unmatched around the 

world by any other make, Longest ele- 
ment 36 ft. Turning radius 20 ft. Shipping 
weight 65 lbs. Shipping container 13 in. 
x 5 in, x 13 ft 

Note: If not available from your dealer, 
order direct You 1 ! get fast, personal 
service. 

Telrex Labs are design engineers, inno- 
vators and manufacturers of the world's 
finest % to 160 meter communication 
systems and accessories priced from 
S25 to $25,000. 

For technical data and prices on com- 
plete Telrex line, write for Catalog PL 71. 



TB5EM 






BALUN 



■ 



Other 
Multi-Band 
Arrays Available 



^ 4 



* 



£ M } A 



TRAP 



Elements shortened 
to show details. 



• ' .■ ■* '■ ■■ ■■. .' 



15M317 

20M326 
2M609 
2M8T4 
6M516 

and — 



TYPICAL TELREX "MONO-BAND" ANTENNAS 

- "Monarch", 10 DBD, 3 El., 4 KWP, 2-1/2" O.D, 17' boom 

- "Monarch", 10 DBD, 3 EL, 8 KWP, 3-1/2" O.D, 26' boom 

- "Monarch", 14 DBD, 6 EL, 6 KWP, 1" O.D, 9' boom 

- "Monarch", 16 DBD, 8 EL, .8 KWP, 1.375" O.D, 14' boom 
-"Monarch", 13 DBD, 5 El., .8 KWP, 1.5" O.D, 16' boom 

many, many more! send for PL-71 Dept. C 



-tel 



rex 



SI 75.00 
$355.00 
S 39.95 
$ 59.00 
$ 63.95 



LABORATORIES 

TV And Communications Antennas Since 1921 
Asbury Park, New Jersey 07712 201-775-7252 






EQUIPMENT REVIEW 




Ed Webb W4FQM/1 
Technical Editor 
73 Magazine 




TR-22 



DRAKE TR-22 

Of all the FM units available to the ham 
today the Drake TR-22 is unquestion- 
ably the most versatile and is an exceptional 
buy. If you are just getting started in FM 
and are looking around for a really universal 
rig the TR-22 is the one that will work on 
base mobile or portable with nothing else 
needed other than the possible exception of 
a mobile or base antenna (if you're more 
than 25 miles from your nearest repeater). 
This little gem is the result of Drake getting 
it all together, and what a package it is, too. 
Here is a 6 channel unit that you can sling 
over your shoulder that has state of the art 
circuitry, a little slim hand mike with re- 
tractable cord, internal rechargeable bat- 
teries, with built in charger and an internal 
telescoping antenna, 

Coming back from SAROC on a United 
flight we asked the captain if we could use 
the TR-22 in flight. Not only did he give us 
permission but he had us moved from tourist 
up to first class so we wouldn't be right over 
a wing that might mess up our radiation 
pattern. Having those 6 channels on the little 




portable unit was a real joy, for as we left 
Las Vegas we said our goodbyes on 94 
simplex and then switched to one of the 
local repeater channels, We talked the re- 
peater out a hundred miles or so and then 
went back to 94 for a while. As we 
approached Denver we started hearing their 
34/94 machine so we switched over to them. 
After a few QSO's we went the 28/88 route 
for some more. Upon arriving back at 
Boston's Logan airport it was even possible 
to hit the 73 repeater on 19/79 on top of 
Pack Monad nock Mountain some 70 miles 
distant. Admittedly our repeater is 2,000 
feet in the air but 70 miles is still quite a 
haul with a watt and a half! 

Before going out to SAROC we had 
crystaled the TR-22 up for the trip and with 
the popout case of the TR-22 it was a very 
simple matter to change the crystals around 
as they are all on top of the board right out 
in the open. Strapping is very easy, too, as 
each crystal has a terminal post right by it 
and jumpers go right in where they are 
needed The transmitter warp trimmer capa- 



APRIL 1972 



25 



citors are right by the transmit crystals and 
the receiver does not need any warp capaci* 
tors. Changing crystals is very easy because 
to get the TR-22 out of the case you don't 
even need a screwdriver. All you do is pull 
out the two little snap releases on the 
bottom of the case and the unit slides right 
out. 

Using the TR-22 mobile is a snap as you 
only have to plug in the external dc power 
cord (so you save your ni-cads for portable 
operation) and plug in your mobile antenna. 
The little unit is so small that you can easily 
slip it into the glove compartment. Thus the 
chance of theft is greatly reduced. It takes 
only seconds to unplug the dc power cord 
and mobile antenna so you can take it with 
you if you don't want to leave it in the car. 
At this point you just pull up the internal 
telescoping quarter wave whip and you are 
working as a portable. 

It is interesting to note that the TR-22 
comes with a complete set of ni-cad batteries 
as part of the unit — not another accessory 
that you have to purchase. The same is true 
for the built in battery charger — it's all 
inside the unit with nothing else to buy. 
When you are at home just plug in the ac 
line cord and the batteries get recharged 
overnight. If you want to monitor at home 
or work the boys a little bit, the battery 
charger gives just enough current to operate 
the receiver so it doesn't pull your ni-cads 
down. Of course when you are listening with 
the ac plugged in, the ni-cads do not get 
charged until you cut the power switch off. 
If you transmit while you're at home then 
that additional current comes out of your 
ni-cad batteries. To check the condition of 
the batteries just turn the squelch control all 
the way counterclockwise and the S/ rf 
output meter gives you a battery voltage 
reading. This same little meter automatically 
works like an 4 *S" meter on receive, so you 
can find a 'hot spot 1 if you're having trouble 
getting into the repeater. On transmit the 
little meter gives you a relative rf output 
indication so you know that you are getting 
out and also gives you some indication of 
how your batteries are doing under a heavy 
load, When your output power starts to fall 
off too much, a quick battery check will 
reveal that the batteries need a charge. The 



ac power cord or any of the external power 
or antenna cords can be plugged right into 
the bottom of the TR-22, even when it is in 
its carrying case. 

The Drake TR-22 is a very rugged 
trouble-free unit. Recently when the 73 
repeater (19/79) pooped out up on top of 
Pack Monadnock and there was quite a bit 
of snow on the access road, we slung the 
little TR-22 over our shoulder before mount- 
ing the snowmobile in zero degree weather* 
While going up the mountain we got a lit lie 
carried away and hit an ice ridge and a big 
wipe-out occurred. After sailing off the 
snowmobile I landed spread-eagled right on 
top of the TR-22! Picked myself up and 
checked back in with K1NUN with no 
problem at all. After finally getting up on 
top of the mountain we worked in unhealed 
buildings for a couple of hours and all the 
while using the little rig. With this kind of 
use that our TR-22 gets, it has got to built 
like the proverbial brick house. The TR-22 
has proved so reliable that Drake has had 
very little warranty work to do and as a 
result has held the $195 price even though 
the U.S, dollar has been devalued by almost 
20% in Japan, 

Drake rates the TR-22 transmitter at 1 
watt (conservative) but we keep measuring 
L5 to 1.6 on the Bird Termline in our lab. 
The receiver is rated at less than 0.5 jLtV but 
actual testing shows very near 0.3 /iV. The 
receiver is double conversion with an FET rf 
stage and a ceramic filter in the 455 kHz 
stage. The first i-f frequency is the standard 
10.7 MHz, ICs are used for the second i-f 
limiter and also for the af output. The 
TR-22 utilizes all solid state switching (no 
relays) for maximum reliability. The instruc 
tion manual for the TR-22 is very complete 
and easy to understand. It contains all of the 
operating instructions, labeled schematics 
with voltage charts for all transistors and 
lCs ? complete pc board pictorials that are 
also labeled, and complete crystal data. 

The Drake TR-22 is a fantastic little piece 
of gear and one of the most versatile units 
we have ever seen with so many normally 
optional features built in as standard 
features. Its performance is as amazing as its 
low price . It is truly a universal rig. 

. . .W4FQM/1 



26 



73 MAGAZINE 



John J. Schuttz W2EEY 
1829 Cornelia Street 
Brooklyn NY 11227 



AN AUTO - BANDWIDTH 

SELECTOR UNIT 



This experimental unit attempts to set the bandwidth 
of a receiver automatically in accordance with QRM 
conditions. Although described as an outboard unit f the 
circuit switching arrangements described can also be 
wired internally in many receivers. 



Many commercial receivers and even 
some transceivers have provisions for 
the independent switch selection of various 
i-f bandwidths for reception purposes regard- 
less of the transmission mode (AM, CW, 
SSB, etc.) switch selling. Generally, most 
operators like to use a wide bandwidth when 
a band is not crowded, because of the tuning 
ease involved, and then switch to a narrower 
bandwidth as QRM conditions develop. It 
would be very handy, however, to have the 
receiver automatically switch to an i-f band- 
width appropriate to the QRM conditions. 
Such operation would be particularly desir- 
able, for instance, when one is working a 
station and using a wide bandwidth and then 
suddenly a strong QRM signal appears. Usu- 
ally, before one can readjust the receiver, 
some portion of the transmission will be 
lost. 

This article describes an outboard receiver 
accessory unit which was developed to pro- 
vide automatic bandwidth selection. The 
unit is complete in itself and makes an ideal 
accessory unit that can be added to a 
receiver or transceiver that does not have 
selectable i-f bandwidths. In the case of units 
which already do have selectable i-f band- 
widths, the switching circuits used can 



adapted in most cases to work with the 

installed i-f filters. The unit provides for two 

automatically selected bandwidths (which 

can be chosen for either phone or CW 

service), although the basic scheme can be 

expanded to include a greater number of 

bandwidth positions. A manual override 

switch is provided for manual selection of 

either bandwidth position. 
Basic Operation 

Figure 1 shows a block diagram of the 
basic stages involved in the selector unit. The 
filter stage is placed between the i-f stages in 
a receiver. It is controlled, through the other 
stages shown, by the level of the i-f signal 
preceding the filter stage. The amplifier stage 
boosts the i-f pickoff signal and then the 
output of this stage is rectified to provide a 
de control voltage. The dc control voltage in 
turn operates a Schmitt trigger stage which 
operates a diode switch for bandwidth selec- 
tion. The i-f pickoff is taken after the first i-f 
stage and not directly after the last mixer 
stage, so the unit will not respond to signals 
greatly outside of the normal i-f bandpass. 
The pickoff could be taken after the filter 
stage, but this will not provide as sensitive a 
response with receivers having good avc/agc 
action, since signals passing through the 



APRIL 1972 



27 























1 

i 














MIXER 






l-F AMPL 


1 

i 


FILTER 
STAGE 




l-F AMPL 












A ! 
























i 














i 














\ 


V 




it 








l-F SIGNAL PICKOFF 






^— STAGE CONTAINS 














TWO OR MORE ARr 
l-F FILTERS R ^ 




AMPL 




RECT 


V 


SCHMITT 

TRIGGER 




DIODE 
SWITCH 








A 

THRESHOLD 






1 

1 
] 








SET 












1 
1 
1 

1 






WANUAL 
OVERRIDE 




1 

l_ 









i 


U.TERNATE «CVR 
UJDIO PICKUP 




i 



Fig* 1. Basic block diagram of the auto-bandwidth unit. Filter stage is inserted between i-f stages in a re- 
ceiver. Diode switch as activated by level of i-f signal causes different i-f filters to be used. 



filter stage will control age action. However, 
the unit can be used in this manner and I he 
control pickup signal can even be the audio 
output signal. 

The unit operates simply on the basis that 
any i-f signal of sufficient amplitude which 
exceeds a preset threshold value will cause 
the diode switch to be activated and switch 
in the narrower of the filters in the filter 
stage. One can devise more elaborate trigger- 
ing schemes where a stage samples and 
integrates the signal levels in the i-f passband 
to determine when the QRM level has 
reached a level requiring a narrower i-f filter, 
but the circuit complexity involved produces 
little in the way of better performance. 
Some provision has to be made so the unit 
will not be activated by extremely short, 
high-energy signals appearing in the i-f band- 
pass — such as a noise pulse - and yet not 
immediately reset the filter stage to a broad- 
er bandwidth after an energizing signal has 
set it to a narrow bandwidth. If the latter is 
not done, the unit would tend to follow a 

i 

high-level CW QRM signal and keep switch- 
ing the filter stage in accordance with the 
keying. The necessary discrimination against 
single pulses and the necessary time delay in 
filter switching is accomplished by a careful 
choice of the components in the rectifier 
stage and by the action of the Sehmitl 
trigger stage. It is in the selection of these 
components and the action of the SchmiU 



trigger stage which mainly makes the unit 
described different from a simple VOX unit 
where such a unit is activated by receiver 
instead of transmitter audio and the VOX 

4 

relay controls the selection of two different 
i-f filters. However, one can, by experiment- 
ing with the circuit time constants, adapt 
many VOX units for use as receiver audio- 
-activated automatic i-f bandwidth selectors. 

Practical Circuit 

Figure 2 shows the actual circuit of the 
selector unit. Discrete transistor stages could 
be utilized but the use of the readily 
available and inexpensive Fairchild fiL 914s 
simplifies the circuitry and is actually less 
expensive than using all discrete compo- 
nents. The first fiL 414 unit serves as an 
amplifier stage and has a frequency response 
that extends from the low audio frequencies 
to about I MHz, The stage, therefore, does 
not have to be modified whether the pickoff 
point to trigger the selector unit is taken at 
some point in the i-f chain of a receiver or at 
the audio output of the receiver. 

The second fiL 914 units is wired as a 
Schmitt trigger. Normally, the output (ter- 
minal 6) of this stage is at nearly ground 
potential. When about 1.5V input is applied 
(terminal 1), the output rises lo almost the 
supply voltage potential (+4.5V). The out- 
put remains at this level until the input 
voltage drops to around LI V. at which time 



28 



73 MAGAZINE 



+ 4.5V 



■ SIS 
iPUT 



455 kHi 

Ojl-F SIG 
OUTPUT 




NARROW 



AMPLIFIER 



SCHMITT TRIGGER 



10-20 pF FOR t-F FREQUENCIES 
5r*vF FOR AUDIO FREQUENCIES 



♦ 

TRIGGER 
INPUT 



Si -Override switch 

Yi-454 kHz (BROAD) 
Y2 -454.7 kHz (NARROW* 
Y3-456 hHl {BROAD) 
Y4-455 3 KHz (NARROW) 



Fig, 2. Circuit diagram of the auto-bandwidth unit. 
The trigger input can he af or an i-f frequency up 
to about 1 MHz. C] L] are chosen to resonate at 
the i-f Frequency being used. Crystal frequency 
spacing is chosen on basis of bandwidth desired. 

the output again returns to about ground 
potential. This % *hold" action on the part of 
the Schmitt trigger, plus the characteristics 
of the rectifier circuit between the two fit 
9\4 units gives the unit the delay character- 
istics previously described as necessary. The 
output of the Schmitt trigger drives a diode 
switch arrangement across a crystal filter 
circuit. Although the diode arrangement 
tends to make the circuit look somewhat 
ml using, the crystal filler circuit is a 
completely standard two-crystal circuit. The 
circuit is centered on an i-f of 455 kHz, The 
4>4 kHz and 456 kHz crystals provide a 
bandwidth of about 2 kHz, while the 454.7 
and 455.3 kHz crystals provide a bandwidth 
of about 600 Hz. Any other bandwidth can 
be chosen by proper spacing of the crystal 
frequencies, as well as any other i-f by 
choosing L and C to resonate at the i-f. 
When the output of the Schmitt trigger is at 
ground potential, the diodes across the 



454.7 and 455.3 kHz crystals are forward- 
biased, and these crystals are effectively 
short-circuited. The diodes across the 
"broad" bandwidth crystals are back-biased 
and these crystals control the i-f bandwidth. 
When the Schmitt trigger is active, the 
opposite condition takes place. The output 
of the trigger stage causes the diodes across 

i 

the "broad" bandwidth crystals to be for- 
ward-biased and those across the "narrow" 
bandwidth crystals to be back-biased. The 
switching action is very fast and noiseless. 
Assuming that an existing i-f strip has 
sufficient reserve gain to compensate for the 
loss in the crystal filter circuit, as most 
receiver i-f strips will, the circuit of Fig. 2 
can be used to build an outboard accessory 
unit for use with almost any receiver or 
transceiver. In those cases where a receiver 
already has built in several i-f fillers which it 
is desired to utilize, the circuit of Fig. 2 can 
still be used and the diode switching arrange- 
ment shown applied to the built-in filters. 

If the diode switching scheme is not 
easily adapted to the filters, the jtiL 914 
Schmitt trigger stage can be used to drive a 
switching transistor which in turn activates a 
relay to switch the i-f filters, as shown in 
I ig, 3. The basic scheme shown can be 
expanded to several more stages of progres- 
sive selectivity by using more Schmitt trigger 
stages, each with a separate threshold con- 
trol to trigger in turn as the output level 
of the first juL ^14 amplifier stage increases. 

Construction and Adjustment 

The unit can be assembled either as an 
outboard accessory unit, or internally in a 



— o 



4.5 V 

I 



6 



BROAD 



TERMINAL 
|iL9i4 

SCHMtTT 
TRIGGER 



NARROW 




DPD.T. CONTACTS 
USED TO SWITCH 
RCVR I-F FILTERS 



6 VOC 
RELAY COIL 



/77 



4 5V 



ANY NPN 

SWITCHING 

TRANSISTOR 



Fig. 3. Instead of using diode switching and an 
external crystal filter, the two fJL 914 stages of 
Fig. 2 can be used to control a relay for switching 
the interal i-f filters in a receiver* 



APRIL 1972 



29 





...TRISTAO'S 
MAGNA MAST 

The new Magna Mast is a 
heavy duty self supporting, 
rotating crank-up mast de- 
signed for ease of installation. 
It utilizes the new Tristao 
Rotor Base with swing over 
design, permitting antenna 
servicing at ground level. 
The Magna Mast's clean tubu- 
lar design will support 1 2 sq. 
ft. of antenna in 60 MPH 
Winds. Its finish is entirely 
hot-dipped galvanized. 

MA-490 49' Magna Mast $324.95 
(With wall bracket, flat 
base & 8' mast) 

MARB-40 Rotor base $204.95 

(Rotor not included) 

MAF-40 Raising fixture $ 94.95 

MA-660 66' Magna Mast $885.95 

MARB-66 Rotorbase $379.95 

(Rotor not included) 

MAF-60 Raising fixture $109.95 

If your requirement is for a tower 
of only 35 feet, let us send you 
specifications and prices on 
Tristao's "Mini Mast". It's a little 
beauty. 

Substantial savings available on 
complete antenna packages. 
— ~.- Please write for free literature. 



Km Radio 

11240 W. Olympic Blvd., Los Angeles, Calif 90064 

213/477-6701 
931 N. Euclid, Anaheim, Calif, 92801 714/772-9200 
Butler, Missouri 64730 816/679-3127 



receiver. The latter type of placement is 
most convenient when utilizing the i-f filters 
built into a receiver. There is nothing critical 
about the construction of the unit except 
the usual precautions of lead dress, etc., 
appropriate to the i-f being used. The thresh- 
old control has to be available as a panel 
control since it requires manual adjustment 
depending upon band conditions and de- 
pending upon the setting of the rf and/or i-f 
gain controls in a receiver (also depending 
upon the af gain control setting if the 
receiver audio output is used to trigger the 
unit). With some practice, the threshold 
control can be set so that the unit is 
activated when the QRM level just exceeds 
that of a signal being copied. 

Results 

Several experiments were tried using the 

unit of Fig. 2 for CW reception with a 455 

kHz i-f receiver. Triggering the unit from the 

first i-f stage output in the manner shown in 

Fig. 1 produced the best results. However, 

audio triggering was also quite effective as 

long as the age circuit in the receiver was 

disabled. The main value of the unit was in 

moderate to heavy QRM situations, where 

very strong signals were apt to suddenly 

appear while a relatively weak station was 

being copied. 

The use of the unit did not completely 

guarantee continued reception of the weaker 
signal because of other factors being in- 
volved such as receiver overload, age capture, 
etc. However, the unit reacted to the WRM 
situation almost instantaneously as com- 
pared to the time required to manually 
readjust the i-f selectivity. Some further 
refinement of the unit is certainly indicated. 
The constant readjustment of the threshold 
control might be eliminated by Unking the 
"base" level for this control with the level 
on the bias line in the receiver as controlled 
by the rf gain control. Nonetheless, the unit 
did demonstrate the real advantage of an 
auto-bandwidth feature for use in receivers 
under today's heavy and suddenly changing 
QRM conditions. With some added refine- 
ments, such a unit should prove to be as 
useful as such accepted receiver features as 
avc/agc 7 automatic noise limiters, etc. 

.W2EEY 



* . 



30 



73 MAGAZINE 



Eric FalkofKlNUN/1 
Assistant Editor 
73 Magazine 



\ 



Break" 



"... so I told him where to get off the 
expressway and I guess he's all right now, 
Steve. Weil, it's getting late, about 1 1:30,50 
I guess PI! knock off and go to bed. Been 
good talkin' to you, WB1ABC, this is 
WlXYZ/'ssshhhkehunk 

"Right, Bill, That guy 11 be OK as long as 
he doesn't go too fast. Ifsa bit slippery out 
there and driving is kind of poor. 1 got in 
only a little while ago and it seemed like it 
was going to get colder and freeze up all of 
this snow that's lying all over the place. 
When you come right down to it, it's really 
not too good out there at all, but as I say, if 
he takes it easy, he'll be OK. Say, before you 
go, can you tell me what's going to happen 
at the meeting Friday? Break." shshshk 
"Break"shshkchunk 

"OK, stand by, breaker. Steve, the meet- 
ing is going to be held at Les's house instead 
of at Mike and Laura's like it was planned. 
Seems like their little daughter caught the 



flu. We're gonna see a slide show about the 
new repeater down in, oh, what's the name 
of that city in Rhode Island? You know 
what I mean, Steve? Break." shshshsk 
"Break"shshsshkchunk 

"Breaker stand by please. Yeah, it's in the 
Bay area. I forget the city you mean, but I 
know what you're talking about. Go." 
shsh"Br — 

"Right. Didn't want to let the tail drop. 
No sense wearing out the relay. Well, the 
pictures will be about I hat new machine 
they're setting up. It should be a good one. 
Say, I'm bringing my wife. Why don't you 
bring yours? All the gals can head off to the 
kitchen while we take in the show. They 
never want to see any of this radio stuff. 
What say?" shshs"Break"shshsk chunk 

"OK. Just a minute, breaker. Good idea, 
Bill. I'll let her know what's happening. I 
know she'll want to see the others. Hey, 
here's an idea. Why not have all the wives 



APRIL 1972 



31 



bring a little home brew something. Since 
Les and the missus are being caught by 
surprise, we all can help out with the 
goodies/' shshsshsh - 

"That's a good one. I'll tell the little 

woman/" shshsh 

Tirst Ihing tomorrow morning Pll get in 
touch with Joe and Mel and have them each 
call a tew of the guys and we can get the 
wives working on this right off. We can make 
a real party out of this. 111 even volunteer to 
leave tor a while and get some pizza it 
anyone wants some. If we get ahold of the 
Sokittoommee VHFers, we could make a 
ha ml est out of I his/* shshsh "Break"shshsh 
skchunk 

"Yeah, and what about this kids? 
shshs — 

"No problem. The high school is on 
vacation now so there should be a lot of 
baby-sitters available. Even on short notice 
It's a natural, shshshshkehunk 

"All right Mien- It's settled. Pll call up the 
host and hostess. Boy! Will they be sur- 
prised. It\s a good thing they have a large 
.house. Some coincidence* eh?" shshs - 

'This is great, But what about the weath- 
er? It looks like il might start coming down 
and l he weatherman says there's a pretty 
good chance of more o( the white stuff and 
some icing over/ 1 shshsh 

"Well, (here are a few hardy souls with 
four wheel drive cars. If it's not too bad, 
they might be willing to make the rounds 
and pick everyone up. There are only ten of 
our guys and six of the Hoommees and 
everyone is pretty close together anyhow/ 1 
shshshskchunk 

"J dunno. It could be pretty slippery, 
even for a four wheel drive, I'm not so sure 
any more that it's a good idea. Like, the 
slides will be good. That s a fact, but if it's 
snowing, the high schoolers won't be able to 
get out for the most part and most of us are 
parents and won't go out ourselves either, on 
a rotten night, it seems like that's the only 
time a family gets together. If it were really 
bad, Pd like to stay in with my family. Wait 
a minute . . . Via listening to a weather 
report . . . high winds . . . slippery driv- 
ing . . . rain, later turning to snow and 
sleet . , . low fog . . , Wow, it sounds pretty 
rotten right now. I wonder about tomorrow. 



Bill." shshsh "Break shshkehunk 

"Hang on, breaker. Y'know, Steve, may- 
be it was a lousy idea after all/' shshs — 

"No, Bill. It's just that the weather is so 
poor and driving is unpredictable. That's all . 
It's a good idea. It's just that the timing is 
off. Maybe for the next meeting we can all 
get together. Iky, I just got another idea. 
How about the two clubs setting up a joint 
repealer, Whadoyou think of that?" 
shshshk chunk 

"1 like (hat idea. What with two sets of 
brains in this town, we should get together 
lo do something like that. I've been toying 
with the idea of putting one up myself/' 
shshs 

"No. Go on, you couldn't do it and you 
know it." shsh — 

"Really, I've even collected all the parts 
for one. 1 just gotta lash them all together/' 
shshsh 

"You're fooling/' shshsh - 

"It's true. You can come over any time 
and see il all/* shshshs - 

"I still don't believe you/" shshshkehunk 

"Well, the proof is in the pudding. Speak- 
ing of pudding, that's what il looks like oul 
there right now, and that's what Til look like 
inside if I don't get some sleep. Say, whal- 
ever happened to that breaker, Omon ahead 
breaker/' shshshskchunk 

1 * Y e a h , c 3 m on a h e a d breaker/" 
shshshskchunk 

"Breaker, speak now or forever hold your 
peace/* shshshkehunk 

"One last chance/ 1 shshshshkehunk 

"Steve, you don't suppose there was an 
accident, do you" shshshshshkehunk 

"No, I doubt it. The guy sounded OK 
when he spoke. I don't think anything is 
wrong/' shshshshkehunk 

**But he tried to break in so many times" 
shshsh — 

"Look. He would have said something if 
something was wrong. Wouldn't he have.*" 
shshshkehunk _ 

"Yeah. I guess you're right. Well, see you 
at the meeting/' shshshshskchunk 

-Right. This is W1XYZ clearing with 
WBI ABC at twelve-thirty on a mucky night. 
G'nighl/' shshsh - 



"CI *nitiht." shshshshskchunk 



KINUN/l 



32 



73 MAGAZINE 



Ed Webb W4FQM/1 

Technical Editor 
73 Magazine 



THE CASE 
FOR TONE ACCESS 



Tone access is the best way to protect 
repeater inputs when two or more 
repeaters share a common Input frequency. 
In many cases the coverage of the repeaters 
overlap each other and a mobile trying to 
access one may bring up several others too. 
This situation is highly undesirable as well as 
annoying to the monitors of the other 
repeaters, particularly if they have automatic 
logging. Tone access can be effective in 
eliminating these unwanted key ups and is 
used in three different modes: Continuous 
Tone Coded Squelch (CTCS), Tone Burst, 
and the "Whistle-Up." 

Of all the tone access systems CTCS is the 
most positive as it will even work when the 
input signal to the receiver is quite noisy. In 
a CTCS system a small encoder is mounted 
in the mobile of base transmitter and sup- 
plies a subaudible tone in the range of 80 to 
180 Hz to the audio input of the trans- 
mitter. Each time the CTCS equipped are 
placed on the air the CTCS tone is con- 
tinuously transmitted at a level that is about 
20% of the maximum speech deviation. In a 
typical narrowband system where the maxi- 
mum speech deviation is ±5 kHz the CTCS 
deviation level is adjusted between ±750 Hz 
to I kHz, The repeater input receiver in turn 
is fitted with a CTCS decoder and this is 
used to control the repeater transmitter in 
place of the usual Currier Operated Relay 



(COR), Thus the repeater can only be 
brought up by an input signal having the 
proper CTCS tone frequency, and when this 
signal goes off the air the repeater will drop 
out even though there is another signal on its 
input frequency. It is the CTCS tone that 
not only brings the repeater up but also 
holds it up and when there is no CTCS tone 
the decoder cuts the keying voltage off to 
the transmitter. (Of course there is normally 
a few seconds drop out time but the repeater 
does drop as this type of control is very 
positive, A CTCS system is fairly secure as 
the decoder will only respond to CTCS 
signals that are within ±1 Hz of the CTCS 
decoder frequency.) CTCS is widely used in 
Motorola calls their system ''Private Line" 
or P.L., and General Electric calls theirs 
"ChannelGuard" or C.G, For those amateurs 
having commercial rigs the installation of a 
CTCS encoder is only a matter of wiring up 
the manufacturer's encoder in the unit. But 
for the ham who has an imported unit or a 
piece of older commercial gear the installa- 
tion of a CTCS encoder has posed somewhat 
of a problem. But recently some small CTCS 
encoders have become available in the price 
range of $15— $25, These types of encoders 
use resonant reeds as the frequency deter- 
mining device and you can figure on spend- 
ing an additional $18.50 for the required 
reed. 



APRIL 1972 



33 



Avcom 1 has also come out with a new 
small CTCS encoder that is quite different 
than the rest in the fact that it does not use 
a reed but a low frequency crystal instead. 
The crystal gives as good as or better than 
the necessary ±1 Hz stability and its cost is 
less than one third of the cost of the reed. 
Avcom calls their little CTCS encoder a 
PL 100 and it is all solid state using both 
transistors and digital IC's, Its dimensions 
are 1.5 x 6.2 x 4.4 cm (0,6 x 2.4 x 1/75 in. 
[H x W x D]), The PL 100 utilizes a crystal 
controlled multivibrator whose output is fed 
to three IC decade dividers to obtain the 
desired CTCS tone frequency. The output of 
the last decade divider is fed to a two section 
low pass filter to obtain a sine output. 
Suppose you want a CTCS frequency of 
1 10.9 Hz (a standard CTCS channel frequen- 
cy) - you would simply use a 1109 kHz 
crystal since the encoder divides its frequen- 
cy by 1000. The PL 100 also has a built-in 
voltage regulator since the logic requires 5 
volts. The encoder will operate over 1 1 to 
15V dc input and has adjustable high and 




Fig, L Avcom PL- J 00 CTCS encoder 




Fig. Z Output waveform of Avcom PL! 00. 

1 Avcom, P.O. Box 29153, Columbus OH 
43229. 



low impedance outputs. The crystals for the 

PL100 are available from JAN Crystals 2 at 

$4 (per crystal) for 100 Hz and $6 for the 

proper crystal for any other CTCS tone. The 

Avcom PL 100 is available in three forms: a 

PC board, parts list, schematic and pictorial 

for $6; a complete kit for $17.95; and the 

completely assembled unit for $24.95. All 

three forms require the addition of a crystal 

that is the desired CTCS tone frequency 

times 1000. 

Tone burst access is the second form of 

tone access systems and is the simplest way 
to go as the frequency tolerances are not as 
critical as those of the CTCS system. Tone 
burst also allows a multichannel or multi- 
tone encoder that can be used on many 
repeater systems. A tone burst encoder is 
simply an audio oscillator whose output 
duration is controlled by a timing circuit. 
The timing circuit can be triggered by the 
grounding of the transmitter push-to-talk 
(PTT) lead or by the application of +12V dc 
to the encoder. Most tone burst encoders use 
the PTT type of keying that grounds a lead 
from the encoder when the mike button is 
pushed. Normally the tone burst duration is 
set at 500 ms. Some tone burst encoders 
have as many as six tone frequencies which 
is more than adequate. This allows the user 
to access a number of repeaters that have 
common input-output frequencies but dif- 
ferent tone burst frequencies. The tone burst 
begins as soon as the operator pushes his 
mike button and lasts for a half second. This 
happens automatically each time the operat- 
or begins a transmission. However the op- 
erator must now remember to pause for a 
half second before beginning to talk thus 
giving the tone burst time to complete. If 
the operator were to speak during the tone 
burst the speech would interfere with the 
tone and the decoder at the repeater may be 
confused at the complex wave form and the 
repeater may not come up. The tone burst 
deviation is normally set to be 60% of the 
maximum speech deviation. A tone burst 
access repeater requires a tone burst decoder 
at the receiver site in addition to the COR. 
Both must give positive outputs before the 
repeater will come up on the air. The tone 

2 JAN Crystals, 2400 Crystal Drive, Fort 
Myers FL 33901. 



34 



73 MAGAZINE 



burst access system has one minor draw- 
back — if there is another signal present at 
the repeater input after the initial tone up 
station goes off the air, the repeater will stay 
up until the three minute timeout time 
drops it out. Normally the tone burst de- 
coder is reset by the COR dropping or by 
the time out timer activating. The tone burst 
decoder also resets the time out timer each 
time a tone burst is received. 

Most tone burst encoders use an LC type 
of audio oscillator that has excellent fre- 
quency stability but requires precision capa- 
citors or padding capacitors to set the 
oscillator exactly one frequency. Other tone 
burst encoders use RC oscillators, integrator 
oscillators, and Voltage Controlled Oscilla- 
tors (VCO). All of these last three types have 
an advantage that the tone frequency may 
be set by the use of pots thus allowing the 
user to have a number of pots and a selector 
switch to select various tone frequencies. 
Each pot can adjust the oscillator over a 
range of about 1400—2600 Hz. These types 
of encoders are easily set to frequency by 
the use of a frequency counter and a 
screwdriver, and shorting the burst timing 
capacitor. 




Fig. 3. Avcom TN421 tone burst encoder 




Fig. 4. Burst envelope of Avcom TN42L Horiz, = 
100 MSfcm* Note: Extra ripple was due to stray 
ac pickup in test gear. 



The Avcom TN421 is an integrator oscil- 
lator type of tone burst encoder using only 
one IC and an RC burst timing network. It is 
so small that it can be mounted in the Drake 
TR-22 with ease. The TN42I is only 1.5 x 
4.5 x 3.8 cm (0.6 x 1 .8 x 1.5 in. [H x W x 
D] ). It only requires the connection of three 
wires to hook to a transceiver: +I2V dc, 
audio to the mike input, and a wire to the 
PTT connection. The TN421 has a frequen- 
cy range of 1400-2600 Hz and has adjust- 
able high and low impedance outputs provi- 
ded. It has a nominal 600 ms tone burst. The 
TN421 is available from Avcom all built and 
ready to go for only $19.95. It will also fit 
in a commercial rig control head. 

The third type of tone access system is 
the whistle-up which is a form of the tone 
burst except that the frequencies used are 
between 1500 and 1800 Hz. The decoders 
are about 100 Hz wide as are the ones for 
the normal tone burst frequencies. Due to 
the lower frequencies the average ham can 
whistle the proper tone and bring up the 

repeater. There are many different types of 
CTCS and tone burst decoders. Most com- 
mercial and ham decoders use resonant reeds 

for the CTCS and LC circuits for the tone 
burst frequencies. 

A new type of tone decoder is appearing 
on the horizon in the form of a Phase 
Locked Loop tone decoder. One such device 
is the Signetic NE-567 and will work with a 
—6 dB signal plus noise-to-noise ratio. This 
gives very impressive performance. Its tone 
decoding frequency may be set by use of a 
pot and a frequency counter. There is no 
input signal required to adjust the NE-567 as 
all that is necessary to do is to monitor the 
VCO frequency with a counter to set the 
decode frequency. The bandwidth may be 
set from a few hundred Hz to about 10 Hz 
depending on your needs. It has a frequency 
range from a few Hz to several hundred kHz, 

So if your carrier access repeater is being 
bothered with unwanted key ups from other 
systems and for if you are being bothered 
with intermod or stray signals, tone access is 
the answer. The equipment is available now 
so you can do something about it rather 
than gripe about it. It's not complicated nor 
expensive and it is a solution that works. 

. . .W4FQM/I 



APRIL 1972 



35 



■ 



Forrest B. Thomas K9MRL 
3335 Central Ave. 
Columbus IN 47201 



CUSTOMIZED 
AFSK-MCW & CODE 
PRACTICE OSCILLATOR 



The complete AFSK-MCW, and code 
practice oscillator using an IC circuit is 
built into a standard 4x2Yax2% in. minibox. 
A printed circuit board is used, and careful 
placement of parts is necessary in order to 
get all the parts into the box. 

Obtain one jack and a plug like the one 
on the transmitter to be used. Mount the 
jack on one end of the box, and bring the 
plug out the other end using shielded cable. 
Mount all components in the box. It would 
be a good idea to tune the coil and check its 
operation first. So, with the switch in one 
position, normal mike control can be used. 
With the switch in the oilier position you 
can key ihe transmitter, and insert AFSK-, 
or MCW at the mike input, and at the same 
lime cut off the speaker. Any combination 
of switching arrangements can be used to 
suit your particular needs, l:ven a small relay 
could be used. 

To use as a code practice oscillator, no 



connections to the transmitter are necessary. 
Plug a speaker into the speaker jack (voice 
coil is not critical). Plug a key into the key 
jack. You can use either the 2125 Hz tone, 
or break the connection at the keyboard 
connection, and use the 2975 Hz tone. 

Sw#l is a 3 pole double throw switch to 
fit your need, and Sw2 is part of the mike 
control system. 

Parts other than CI, C2, and C3 are not 
critical. These should be mylar capacitors. 
Do not use ceramic or disc capacitors since 
these tend to cause drift. 

Tuning olLl can be done by varying the 

capacity of CI and C3* or taking turns off of 

LI . For best results you should be very close 

to frequency. With the keyboard jack closed 

you should have a 2125 Hz tone; with it 

open you should have a 2975 Hz tone. In 

some cases a polar relay, a high speed relay, 

may be necessary across the printer contacts 

to key the oscillator, 

. . .K9MRL 

33 22 



r^bt 




KEY 

BOARD 



MOTOflOLA Wtl 
MIKE HI 

SPK. 



SHELL* 
JGNDI 

RELAY 



<»• P t.TJ 

emmt 



MIKE LOW 




Fig, I. Integrated circuit AFSK-MCW or code practice oscillator. 



36 



73 MAGAZINE 



Raymond Megirian K4DHC 

Box 580 

Deerfietd Beach FL 33441 



USING THE LM 373 



About 2 years ago a new integrated 
circuit was announced by National 
Semiconductor and was labeled the LM373. 
Inside the little T05 can were the makings 
of 4 gain stages, an age section, a balanced 
mixer and a peak detector. At least that's 
what the poop sheet said, and circuits were 
shown for using the little jewel in various 
types of i-f strips. I was fortunate at that 
time to acquire an LM373 and promptly 
breadboarded an SSB i-f strip to see how it 
would perform. It performed amazingly well 
and I was sufficiently impressed to start 
planning a receiver designed around this new 

IC. 

Although I didn't know it at the time, all 

the ingredients for a classic demonstration of 

Edsel Murphy's Law were gathering for the 

final curtain. The clincher came when word 

got around that the manufacturer had 

thrown in the towel. That's when Murphy 

struck and left me with a crisply burned 

collector's item. 

Now, 2 years later, I once again own an 
LM373 and have been assured by the com- 
pany rep that these items are here for keeps 
and are available from distributors. 

The present LM373 is basically the same 
as its predecessor, including pin connections, 
although internal circuitry is somewhat 
changed. The device will perform many 



diverse functions which make it adaptable to 
AM, FM, or SSB i-f systems by merely 
changing a few connections. In the applica- 
tion described here, the IC is used in a 
receiver capable of operating in either AM or 
SSB modes. It was made small only because 
my hangup is miniaturization. It is designed 
to cover 3.5 to 4.0 MHz and an all-band 
converter will someday be used ahead of this 
^tuneable*' i-f. If the cabinet had been about 
an inch larger, I might have gone all the way 
right from the beginning. 

Let's take a look at this new device and 
see how it may be used to perform the 
functions of particular interest to the ham. 
Figure 1 shows how the various sections of 
the circuitry are tied together internally and 
which points arc brought oul to pin connec- 
tions. Note that l lie IC is divided into 2 
separate areas having no common internal 
signal path. The upper portion, consisting of 
2 gain stages and the age section, is exter- 
nally coupled to the remaining circuitry by 
the main selectivity determining device. This 
usually consists of a mechanical, ceramic, 
crystal or LC filter operating in the 50 kHz 
to 15 MHz frequency range. 

In order to better understand just how 
the various sections of the LM373 can be 
made to perform the desired functions, let's 
look at some block diagrams. Figure 2 shows 






APRIL 1972 



37 



^M 



Vcc 



AGC INPUT 
WAD CAPACrOR 
SWITCH 



AGC STAGE 

OUT 



LOW LEVEL RF IN* 2 



DC f ElQ9ACK 
BYPASS 




PEAK DETECTOR OUT 



QUADRATURE DET/ 
AMPL/PROD OET 
OUTPUT 



FIXED GAIN 
STAGE 1N 



FW QUADRATURE / 
AM MIXER UNBALANCE 
SSB BFO INPUT 



Fig* J f Pin connections and internal wiring of 
theLM 373. 



the connections used for operating in the 
AM mode. In order to disable the balanced 
mixer for this mode, an offset voltage is 
introduced at pin 6 by means of a resistor. 
Age voltage is taken from the output of the 
peak detector and connected to the age 
input at pin 1 through an RC network with 



the desired attack/decay characteristic. An 
age range of 70 dB with operation down to 
50 juV mis input is possible with this circuit* 
For SSB/CW operation, refer to the block 
diagram of Fig. 3- A bfo signal of 25 mV rms 
or greater is fed into the balanced mixer at 
pin 6, causing the mixer to act as a product 




+ I2V 



Fig. 2, AM i-f block diagram. 



38 



73 MAGAZINE 



5SB/CW, 
l-F IN 




AGC 



+ IEV 



L -@ © (p— 






ft? 




—- ®J 



SSB 



AGC 






A^ 



+ I2V 




SS8 AUDIO 
OUT 



1 



MANUAL 

GAiN 

CONTROL 



Fig, 3, SSB/CW i-/ biock diagram. 



detector, The peak detector generates an age 
voltage derived from the audio fed to it from 
the product detector. This voltage is fed 
back to the age section through t he RT 
network. A means of providing manual gain 
control for CW operation is also shown in 
the block diagram. So here we have an i-f 
amplifier, a fast attack, slow release audio 
derived age system and a double-balanced 
product detector all in one neat package. 

Although I have not tried the LM373 in 
an FM receiver, some readers may be interes- 
ted in this type of operation and Fig. 4 is the 
block diagram for an FM i-f system. By 
grounding pin 1, the age is defeated and all 
gain stages become symmetrical non-saturat- 
ing limiters. This action also connects an 
internal quadrature capacitor to pin 6 which 
is also input A of the quadrature detector. 
An LC network tuned to the nominal i-f 



frequency is connected externally to pin 6. 
This network produces a frequency-depen- 
dent phase shift with respect to the signal at 
input B of the quadrature detector. A pulse 
duration modulated output is produced by 
the detector and integrated by the capacitor 
connected to pin 7, The Q of the quadrature 
network will influence both the output level 
and the distortion. For a given deviation, 
increasing Q will increase both output and 
distortion, At least a 50 mV rms signal is 
required at pin 6 to ensure switching action 
of the detector and maximum output. Audio 
at a higher level may be taken from the 
output of the peak detector at pin 8. 

In addition to the applications above, this 
versatile IC may be used in several other 
interesting circuits. These include SSB gener- 
ator with ale, constant amplitude/amplitude 
modulated rf oscillator, first i-f amplifier/ 



FM I-F - \ 



Vcc 
+ I2V 




AUDIO 



Fig. 4. FM i-f block diagram, 



APRIL 1972 



39 



• L! 






LEADERS IN COMPACT ANTENNAS • 




MAXIMUM EFFICIENCY/ MINIMUM SIZE 

FOR APARTMENTS •SUBURBAN HOMES 
, Marine and Portable Operation 

\ / Packaged for APO and FPO Shipping 

<^Jau models completely weatherphoofed 

b-24 + rk-3 combination 

3 elements 

10-15-20 
l>!^ METERS 




PATENTED 



The features 
of the popular 



10 15-20 Meters B-24 plus the 

RK-3 



Bands 

■~ z — ; —~~~" — _ r « new RK-3 re- 

Power Rating 1400 Watts P. E. F. f lector kit 

Total Boom Length ir make a M- 
■ ^ r njque 3 ele- 

Turning Radius 7'-10* ment cornbi- 

nation.Choose 



Total Weight 



^3 lbs, the combina 



Single Feed Line 



52 ohm ta^the 
RK-3 to your 



SWR at Resonance L5 to LO max. present B-24 
■ and enjoy the 

B-24 + RK-3 Combination Net $94.95 L^5T£nt 8a i« 
IK-3 Reflector Kit (only) Net $36.95 back 




Patented 



Bands 



6-10-15-20 Meters 



Power Rating 
El. Length 



1400 Watts P.E.P, 



11' 



Turn. Radius 



V 



Total Weight 



13 lbs. 



Single Feed Line 52 ohm 



SWR at Resonance L5 to 1.0 max. 



6-10-15-20 

METERS 

The time proven 
B-24 4-Band an- 
tenna combines 
maximum e f f i - 
ciency and com- 
pact design to 
provide an excel- 
lent antenna 
where space is a 
factor, New end 
loading for max- 
imum radiation 
efficiency. No 
center loading. 

Model B-24 
Net $62.95 



MULTIBAND COAXIAL ANTENNA 
for 8-10-15-20 METERS 

Needs no ground plane radiate. Full electrical 
Vz wave on each band. Excellent quality 
construction. Mount with inexpensive 
TV hardware. Patented. 



1 « 



Power Rating 



1400 Watts PEP, 



Total Weight 



6 lbs. 



Height 



11' 



Sing le Feed Line 52 ohm 

SWR at Resonance L5 to LO max. 










Model C4 Net $36.95 

See our entire tine at your nearby distributor 

or write the factory for further information 

and literature. 




Call 814-454-2171 



1001 W. 18th Street • Erie, Pennsylvania 16502 



vcc 
+I2V 



f 



1 



t»F 



JOOK AGC 
THRESHOLD 
(OPTIONAL) 



AUDIO 



AM l-F 



.005 yF 




FILTER 



Fig. 5. AM hi strip wiring diagram. 

second mixer and as a video amplifier with 
age, manual gain or gating. There axe others 
too, but unfortunately we can't cover them 
all at this time. 

If you are mainly interested in using the 
LM373 in your own designs, Figs. 5, 6 and 7 
are schematics for use in the various modes 
discussed above. Notice that in all circuits, 
ac coupling is used for signal transfer. Dc 
paths in integrated circuits of this nature can 
cause excessive currents to flow, resulting in 
possible destruction of the IC. The bypassing 
at pin 3 should be accomplished with a low 



vtc 

M2V 



+Vcc 



I 



MAN GAIN 
FOR CW 



25 *iF 




20K 




AUDIO 
OUT 



05jjF 



25 mV 

ORMS 
8F0 IN 



Fig. 6. SSB/CW i-f strip wiring diagram. 



40 



73 MAGAZINE 



MEMORY-MATIC 500 KEYER 

Today's newest and most advanced keyer\ 500 
bit/40 character Read-Write memory. Stores any 
message instantly, Near-Full and overload alarms* 
Includes all Space-Matic 21 features. 

$198.50 



SPACE! 




21 KEYER 



Instant self-starting, self-completing dots* dashes, 
and associated dot, dash, character and word 
spacing. Adjustable weighting. 3.5-85 wprn. Built- 
in sidetone and speaker. Iambic. Dot and dash 
memories. Suitable for use with all standard keys. 

$89.50 




FREQUENCY MARKER STANDARD 

Markers at 5> 10, 25, 50, 100, 200 and 400 kH2. 
400 kHz crystal. No unwanted markers. Latest 
low power ICs. Buffered osc. and output. 

$32.95 (Less Batteries) 




ELECTRONIC FEATHER TOUCH KEY 

The solid-state design detects the mere touch ol 
your finger and eliminates such problems as 
contact bounce, proper adjustments and dirty 
contacts. Weighted. 

$19.95, $22.95 SPOT Switch Option 




5-year guarantees 



PPD USA • Send for brochures 




Data Engineering Inc 



Box 1245 Springfield, Va. 2 2151 



FM l-F 




^OUT 



Tl* COILS ARE \Z TURNS 

NO, 34 AWG WIRE ON 

1/4 in. FORM r WPTH 

3/8 in. CARBONYL OUT 

"E* CORES SEPARATED 500 

TO OBTAIN TRANSITIONAL P F 

COUPLING, 



Fig. 7, FM if strip wiring diagram shown with 

transformer interstage coupling, 

inductance high frequency capacitor and a 
larger tantalum for the low frequencies. You 
should also observe the usual rules of good 
layout practice and keep leads short when 



working with high gain circuits such as this. 

Figure 8 is a schematic for the front end 
of the receiver I built using the LM373 in 
the i-f system. The rf and hf oscillator stages 
both use an inexpensive 2N3819 plastic 
junction FET. The mixer uses a dual gate 
MOSFET, Another 2N3819 is used as a 
source follower to isolate the hf oscillator 
and prevent pulling. A small transistor type 
i-f transformer couples the mixer to the 
LM373. 

Figure 9 is a schematic for the remainder 
of the receiver; including the i-f, bfo and 
audio portions. In order to operate the i-f 
system in both AM and SSB modes, it was 
necessary to incorporate a 5 -pole, 3 -posit ion 
switch, SK to make the transfer. Two of the 
poles are used to switch the age time 
constant components from AM to SSB. 
Another pole provides bfo input to pin 6 for 
SSB operation or an offset voltage for AM. 
Pole number 4 selects audio output from pin 
7 for SSB or pin 8 for AM. The final section 
applies voltage to the bfo for SSB/CW 
reception. S2 is a small SPDT toggle switch 



APRIL 1972 



41 



used to go from manual gain control to 
normal age when in the SSB/CW mode. The 
manual gain control is useful when listening 
toCW. 

A second i-f transformer is used for the 
bfo tank and is tuned by a dc voltage applied 
across a capacitor diode, I used a V47 but 
many ordinary silicon diodes will work 
satisfactorily in this application. Epoxy rec- 
tifiers are also a good bet. Depending on the 
frequency variation obtained, the 27 pF 
series capacitor may have to be altered for 
proper tuning range. If range is insufficient, 
increase the value of the series capacitor. If 
bfo range is greater than needed, a smaller 
capacitor may be used. 

Operating voltage for the hf oscillator, 
the bfo and its tuning diode is regulated by a 
zener diode. Almost any small zener in the 
region of 6 to 7V may be used. The 
base /emitter junction of a silicon transistor 
makes an excellent zener and no doubt 
several can be found with 6 to 7V break- 
downs. With these critical circuits regulated, 
the main supply can be varied from 9 to 15V 



without producing any noticeable change in 
the received signal other than audio output. 
A 2N3819 source follower further stabilizes 
the bfo. 

Because I wished to keep size to a 
minimum, I used a tiny 455 kHz ceramic 
ladder filter as the interstage coupling device 
for the LM373. This filter, the Murata 
CFS455J, has a 3 dB bandwidth of 3 kHz 
and is adequate for general use. I used a 
printed circuit board for assembling the 
receiver and arranged it to take either the 
ladder filter or a Murata SFD-455B dual 
section filter. This provides about 4.5 kHz 
bandwidth at 3 dB, Because this is not a 
construction article in the strictest sense, 
and because some of the components dic- 
tated board layout not compatible with 
most junkboxes, a printed circuit layout has 
not been included. 

I incorporated an audio preamp since I 
like to have a little reserve when it is needed. 
This stage can use almost any NPN audio 
transistor and is not at all critical. The 
transistor I used was an unmarked refugee 



35-4,0 

MHz IN 



2N30I9 




UNLESS OTHERWISE SPECIFIED: 
ALL CAPACITORS IN pF 
ALL RESISTORS 1/4 W 
Clo, Clb, Clc - MITSUMI NO. 3C20 
3 -GANG, 20 pF 
PER SECTION 
LI, L2-75 TURNS NO. 34 AWG 

ENAMELED WIRE PRIMARY 
WINDING 6 TURNS SAME 
WIRE. 
L3-60 TURNS NO. 34 AWG 

ENAMELED WIRE. 
ALL COILS WOUND ON MICROMETALS 
NO. L45-2-CT-&-4 SHIELDED FORMS. 



Fig. B. Schematic of the front end of K4DHC*$ receiver. 



42 



73 MAGAZINE 




3 9* 




3 J* ^J) o^-fl 1 /p 



005 



51-5 POLE, 3 POSITION ROTARY SW 
POS i - AM 

POS .2 - STANDBY [SHOWN IN ST AMDS Yl 
POS 3~SS8/CW 

5Z-S.P.0.T TOGGLE SW. 



8a 



MC K54 
BOTTOM VIEW 



Fig. 9, Schematic of the bfo, i-f and audio portions 
of K4DHC i receiver, 



from my junkbox. A Motorola MC1454 IC 
power amplifier is used in the audio output 
stage* It is capable of 1W of audio into an 
812 load. I've had excellent results with this 
IC and have used it in many projects. The 
small speaker built into the receiver doesn't 
do the audio justice, but does make the 
receiver self-contained. 

At present a block of 8 pen cells soldered 
in series powers the receiver. No-signal cur- 
rent drain is about 28 mA, rising to 40 or 50 
mA on audio peaks at normal room level. At 
these levels it is not necessary to heatsink 
the audio amplifier. 

Construction of the receiver is unortho- 
dox in some respects because of my desire to 
keep it small. Since some of the ideas used 
here may be of interest to others, I'll go over 
the main points. 

The front end tuning capacitor is a tiny 
3-gang film dielectric type of 20 pF per 
section. It is driven by an equally small 4.5 : 1 
ball drive attached directly to the tuning 



capacitor. Unfortunately, a pointer was not 
available for this drive but one was fashioned 
quite easily and can be seen in the photo- 
graph. The 3 trimmers, Erie style 538, were 
mounted on the capacitor and the whole 
assembly fastened to the front panel along 
with the other controls. This saved consider- 
able board space and did not add anything 
to the space required behind the front panel. 




The 3-gang miniature tuning capacitor with reduc- 
tion drive attached. Homemade pointer is push-fit 
over the large (direct) shaft. 



APRIL 1972 



43 



An additional saving was achieved by mount- 
ing as many components as possible on the 
mode selector switch, SL Since panel area 
was scarce, I used a small diameter Japanese 
rotary switch having 3 decks with a total of 
9 poles and 3 positions. This is a Lafayette 
part number 99F61715 which lists for only 
794* Since it is a shorting type switch, it was 
necessary to use position I and position 3 of 
each section to avoid shorting circuits during 
transfer. An unexpected bonus resulted, 
however, when the middle position worked 
out fine for "Standby." Since the switch has 
many more contacts than required, unused 
lugs made convenient tie points for mount- 
ing the associated resistors and capacitors. 
With these savings, the printed circuit board 
for the entire receiver ended up being a 3-in. 
square. 

I think that most will agree that the 
principal limiting factor in shrinking equip- 
ment size, is front panel space. Half-inch 
knobs seem to be the smallest practical size, 
and even then you need finger room in 
between controls. The Ten-Tec cabinet I 
used is the smallest of their JW series. Actual 
panel space is 2 J A x 3-5/8 in. As can be seen 
in the photograph, there isn't much room 
left over. 

If you build up a copy of this receiver 
and use the specified coil forms, a suggestion 
may be in order. After alignment is com- 
pleted, put a small ball of coil wax in the 
opening of the oscillator coil and melt it 








K4DHC's miniature 75 meter receiver utilizing the 
LM373 in the i-f system. 



Interior view of the receiver, The LM 3 73 is just 

behind the i-f transformer in the middle of the 
hoard. The 3 kHz ceramic ladder fiiter is just to the 
right The pen cell battery pack normally sits in the 
space between the board and back panel of the 
cabinet* 

down with the tip of a small soldering iron. 

The bobbins in these coil forms sometimes 

do not fit tight and cause microphonics or 

instability in the oscillator output. The wax 

holds the bobbin tight and prevents any of 

these problems. 

That covers the basic uses of the LM373 

and may have set you to thinking about 

applying this versatile device to some of 

your own pet projects. It should be pointed 

out that the version discussed here is the 

limited temperature range LM373H in a T05 

can. Price is 54.85 in small quantities, A 

14-pin DIP version, the LM373N, was to be 

made available at slightly lower cost but I 

hadn't checked on this at the time of 

writing. 

For those who may be interested, I have a 
limitied supply of the uncommon com- 
ponents used in the receiver. This includes 
the 3-gang tuning capacitor, the hall reduc- 
tion drive, Murata filters and shielded coil 
forms. Drop me a line for information. 

Results to date using this i-f system have 
been quite gratifying. The LM373 provides 
more than adequate i-f gain at 455 kHz and 
the age acts without any noticeable pump- 
ing. Overall, the use of this device has 
drastically cut component count while pro- 
viding excellent circuit performance. 

If you are wondering about the weird 
nameplate on top of the receiver, it came 
about because I had to cover some bad 
scratches and it seemed the only way to do 
it 

■ . -K4DHC 



44 



73 MAGAZINE 



Ken W. Sessions, Jr. K6MVH 



REPEATER 



SITE 



BREAK- IN ALARM 



Lets you hear what the burglar is saying as he robs you blind. 



It was very warm in my non -air-condi- 
tioned repeater building and I had been 
working through the most scorching period 
of the hottest day of the year putting in a 
new control system, I was tired and dusty 
and irritable and impatient, I just wanted to 
get home. So, when it was well past time for 
supper, I made a batch of temporary alliga- 
tor-clip connections to keep the repeater 
operational and went on down the hill. Since 
I planned to return first thing in the morn- 
ing, I left all my test equipment and tools at 
the site. 

When tomorrow rolled around, I was still 
tired. The repeater seemed to be perking 
right along without nny trouble, so I put off 
making the trek. It wasn't until a week had 
gone by that the repeater finally crapped out 
completely and I had to visit the site. And 
when I did, I wished I'd returned the day 
after my earlier visit. When I unlocked the 
building and went inside, I was stunned. My 
test equipment — some of it borrowed — was 
gone! My tools were gone! The only thing 

APRIL 1972 



remaining intact was the repeater itself, I 
had been robbed! 

Someone had either jimmied the door or 
somehow managed to unlock it. My initial 



-I2V 



I 



MAGNETIC 
REED 

SWITCHES 
{I FOR EACH 
ENTRY POINT) 



Pr 



:470jv 



T 



CONTROL (RESET) 



HEP 
320 




ic: 



INTERCOM 
TRIGGER 
(SEE FIG. 2) 



Fig. 1. Basic repeater intercom alarm. After the 
circuit has been triggered, any short pulse applied 
to the reset relay will cancel the alarm t resetting 
the system. 



45 



reaction, after that first shock wave, was 
fury - but not fury at the thief: I was angry 
with myself! I had a superb automatic 
communications system up there that could 
have been used to warn me of an unwelcome 
intruder. But I had not had the foresight to 
use it for that purpose. Then and there I 
made up my mind never to install another 
repeater without an automatic alerting de- 
vice to Let me know when the site is being 
"visited," Admittedly, that was like locking 
the corral after the steers have been rustled, 
but at least I could be relatively certain of 
hanging onto the next herd. 

Getting an alarm into service was pain- 
fully simple— the fact of which simply 
served to make me even more upset with 

myself for not thinking of it sooner. 

Thinking that the thief (or thieves) might 

return for more of my goodies some day, I 
decided to employ a warning system that 
was covert by nature: that is, I wanted to be 
alerted that someone was tampering, but I 
didn't want to alert the tampererto the fact 
that I knew he was messing around where he 
didn't belong. So my idea was to use an 
intercom system connected to a door-actu- 
ated switch, which would key the UHF 
control repeater and let me actually hear 
what was happening on the hilL (I didn't 
connect the intercom to the regular open 
repeater because I couldn't help thinking 
that the thief could be someone who moni- 
tors and uses it - unlikely as that thought 
seemed to be,) 

Alarm Circuit 

The basic circuit I used for triggering the 
alarm system was similar to the one shown 
in Fig. I. The circuit pictured here, developed 
by Motorola engineers as an automobile 
burglar alarm, draws less than 1 mA of 
constant current, so there's no need to 
worry about power requirements, even if 
your repeater is battery operated. Since the 
voltage required is on the order of 12V, a 
dropping resistor would be in order if you 
plan to operate from a 28V dc control 
system. 

If your repeater site employs a UHF 
control repeater in conjunction with an open 
repeater in the VHF band, you'll probably 
want to employ the same operating phi* 



losophy that I used. 1 connected the alarm 
so that when it is actuated, the open 
repeater goes off the air and the control 
repeater goes on. This is accomplished by 
rerouting some of your existing audio con- 
nections. Cut the 2m push-to-talk lead that 
keys the UHF repeater and reroute it 
through the normally closed contacts of the 
alarm relay. Do the same with the 2m audio 
lead. The rerouted leads are shown in Fig. 2, 

The way the system works is simple: The 
open repeater normally feeds signals to the 
UHF repeater through the alarm relay con- 
tacts. But when the alarm circuit is triggered, 
the UHF repeater becomes completely disen- 
gaged from the 2 m repeater (even though 
the 2m system can continue to function 
independently, without UHF interconnect, 
if you want it to). The alarm circuit keeps 
the UHF repeater on the air until you, at the 
control point, transmit a tone command to 
reset the alarm. 

While the alarm is actuated, the UHF 
transmitter mike circuit is being fed with a 
special homebrew microphone — comprised 
of an ordinary speaker and an output trans- 
former. (The output transformer, by the 
way, can be any old tube-type "plate-to- 
voice-coil" transformer such as the type 
typically found mounted on the back of 
speakers in ac-dc broadcast-band radios.) 

The higher the impedance of the mike 
side of the transformer, the better — but if 
you get hum, you'll have to use shielded 
wire and perhaps enclose the transformer in 
a chassis all by itself. 



INTERCOM 
TRIGGER 
RELAY 
CONTACTS 




-<FROM 2M RT.T 
♦ TO UHF RT.T. 



J AUDIO FROM ZM 



*RPTR RCVR 



♦TO XMIT AUDIO 
CKT 



OUTPUT 
XFMR 




PM SPEAKER 



Fig. 2. The existing repeater-to-UHF audio inter- 
connects should be reourted through the intercom 
trigger relay so that the UHF control repeater hears 
only the action at the site in the event of a 
burglary. 



46 



73 MAGAZINE 



Make a few checks after you get the 
contrivance wired up just to see if the 
intercom is sensitive enough to pick up soft 
voices from anywhere in the repeater build- 
ing. If not, just incorporate a simple audio 
amplifier between the speaker "mike" and 
the transmitter's audio line. 

You may want to use the same approach I 
did with respect to keeping the mike hidden. 
I used the built-in speaker on the rpeater 
cabinet as the mike, (It doesn't have the best 
audio quality in the world and would never 
win any fidelity awards, but it did the job.) I 
installed a switch so that when I was 
working on the repeater I could use the 
speaker as it was originally intended. The 
hook-up for this is shown in Fig. 3. 

If you use this technique, you'll have to 
remember to reposition the switch to the 
ALARM spot when you're ready to leave the 
site; otherwise you'll hear nothing when the 
burglar makes his appearance. 

Triggering 

Every repeater site has its own individual 
weaknesses from the standpoint of burglary 
susceptibility. Since my site had but one 
door and no windows, my problems were 
minimal. I simply installed a magnet on the 
door and a magnetic reed switch adjacent to 
it on the wall. If your site has more than one 
door, or a window or two, you'll want to 
install a magnetic reed switch at each pos- 
sible entry point — or use the photoelectric 
alarm approach described later. 

There's no requirement for using magnetic 
reed switches, but they offer the advantage 




i 



•J 



ALARW / NQRHAL 
O 



+ RPTR RCVR AUDIO 



LOZ 



■*» TO MIKE CIRCUIT 



Hf Z 



ft? ft? 



Fig. 3. A simple switch can be used to make your 
repeater receiver speaker double as an intercom 

microphone. 

APRIL 1972 



of being very small and highly reliable. Also, 
it will mean that you won't have to run a 
wire across the door itself. 

Relays 

The reset relay should be capable of 
operation from whatever dc control voltage 
your particular repeater system uses. Since 
nothing more than momentary opening of 
the contacts is required, virtually any con- 
trol system that can provide a short voltage 
pulse on command will be adequate. 

The intercom trigger relay is a Potter- 
Brumfield type RS5D, which has a 6V dc 
coil whose resistance is 33512, You should 
stick to that relay or its equivalent if you 
don't want problems. A lower value of coil 
resistance could cause excessive current to 
be drawn, possibly resulting in thermal 
destruction of the semiconductors. Higher 
resistances are all right, of course, but make 
sure the relay contacts will be able to handle 
the loads you'll be switching. The P-B relay 
shown can handle loads of up to 2A ? which 
should be more than adequate for the 
push-to-talk and audio requirements of most 
repeaters. 

The diode across the relay coil provides a 
discharge path for any induced voltage 
spikes. Without it, the coil's collapsing field 
can generate a momentary high-voltage spike 
that might be too much for the semiconduc- 
tors in the circuit. Don't install the diode 
backwards, either, or the diode will shunt 
the direct current around the relay coil 
directly into the SCR — which could mean 
curtains for your HEP 320. 

Alternate Approach 

If your site doesn't lend itself well to 
installation of magnetic reed switches, or if 
there are other groups who use your build- 
ing, you might want to try a protection 
system that is less likely to be triggered 
inadvertently. One such method involves the 
installation of an "electric-eye" across the 
area in the building adjacent to where your 
repeater is located. 

If you use this approach and there are 
other lessees in the same building, be sure to 
let them know of the alarm so they won't 
trip it when they're working on their own 
equipment. 

47 






— 



-12 V 



"€) 



■»- 




IK 



* »f- 



O CONTROL (RESET) 



^ 



(Ok 




Fig. 4, The alarm circuit can be easily adapted to a 
photodiode beam-type protection arrangement by 
replacing the reed switches with a photodiode and 

a resistive shunt 



As you can see by comparing Figs. 1 and 
4, there aren't many differences between the 
two alarm systems. All components that are 
unmarked in Fig, 4 5 as a matter of fact, are 
of the same value as those shown in Fig. 1. 

You'Il need a simple lens assembly to 
focus light from the source across the access 
path to the photodiode. This shouldn't 
prove any great problem, though, because 
any old flashlight should prove capable of 
handling that job with ease. You won't want 
to use batteries, of course, because they'd be 
gone before you could even get to the 
bottom of the hill. Just replace the batteries 
with a dc voltage from your normal control 
system. 



HEP 55 



pL 




SENS 
ADJ 




Fig. 5. Addition of a HEP 55 amplifier and 
substituting a pot for the fixed resistor in Fig. 4. 
will considerably increase the sensitivity of the 
circuit and will permit the light beam to span a 
greater distance. 



If the flashlight can't provide a good, 
fairly high-intensity spot of light, you can 
modify it by moving the bulb back and forth 
within the reflector until an effective spot is 
obtained. Most flashlights will be good lor 
about 6 ft. You can increase the sensitivity 
of the alarm circuit, though - thus increas- 
ing the beam distance capability - by adding 
a simple amplifier circuit as show h in Fig. 5. 

The high-sensitivity amplifier and photo- 
diode go into the circuit at the point in Fig. 
4. where the photodiode and 1 kfl resistor 
are connected- As you can see, the 1 k£2 
resistor is still in the circuit, but now it's in 
the form of a pot so that circuit sensitivity 
can be adjusted. 



COLLECTOR 




(j 



EMITTER 



Fig. 6. Photodiode symbol and bottom view of 
Motorola's HEP 312. 

If you haven't worked with photodiodes 
before, you might not be familiar with their 
layout. Figure 6 shows the symbol and the 
lead layout of the HEP 312, As you can see,- 
the photodiode is a two-lead device, and it 
consists of a single PN junction. When light 
strikes the little collimator lens, current flow 
across the junction increases. With the junc- 
tion reverse-biased, the increase is substan- 
tial. 

Naturally, the lens of the photodiode has 
to be oriented for best light-capturing abili- 
ty. If the repeater site is well illuminated, 
you'll have to put a Ittle tubular shield 
around the diode to keep it from being 
triggered by extraneous light. 

Semiconductor Availability 

All the Motorola HEP devices described in 
this article are available from Circuit Special- 
ists, Inc., Box 304? \ Scottsdale* Arizona. 
The magnetic reed switches are available 
from GC Electronics, Division of Hydro- 
metals, fnt\, Rock ford, Illinois 61 101. 

...K6MVH 



48 



73 MAGAZINE 



John G. Oehlenschlager K0MOC 
394 -D Ricketts Road 
Monterey CA 93940 



MOTOROLA T44 BASE 

STATION CONVERSION 



Conversions of the Motorola T44 450 
transceiver to 100V probably come in 
as many versions as there are persons con- 
verting them. Although not guaranteed to be 
the ultimate, this conversion does offer two 
distinct advantages, simplicity and versatili- 
ty, A very minimum of time and com- 
ponents is required. Most of the parts are 
readily available from the average junkbox. 
The only items which may present a prob- 
lem are the 6.3V transformers. The conver- 
sion in no way impares the operation of the 
T44 on 6/1 2V dt\ All that is necessary to 
change from mobile to base station is to 
remove the vibrators and insert the jumper 
plugs, and position the control voltage selec- 
tor to ac. Fuses F3 and F4 must be replaced 
with 20 amp fuses. 

The first step in the conversion is to 
prepare the two vibrator jumper plugs. Any 
of several methods may be used: however, 
the easiest method is to cannibalize a pair of 
burned out vibrators for their bases or use an 
old 7 pin tube base. Alternatively, short 
pieces of 10-gage wire will fit into the 
vibrator sockets quite nicely. The function 
of the jumper is to short pins 1 and 5 to pin 
7 (ground). (Sec Fig. I ) 

The next step is to locate the small brown 
wire connected to terminal 3 of terminal 
strip TBI. (TBI is the second transverse 
terminal strip from the front of the power 




supply/) Unsolder this brown wire from 
terminal 3 and move it to terminal 6 of TBI. 
Then wire in selector switch, connecting the 
two diodes and capacitor as shown in Fig. 2. 




10 



© 



■*> TO PIN 4 OF El 



© 

6 




-AC 



© 



BROWN 
WIRE 



ORIGINAL /T\ 
CONNECTION^" 



DC 



ZL 

^Ts250 *iF 



♦ TO PIN 2 OF El 




© 

Fig. 2. Terminal board 1 (TBI) 

Then connect terminal 8 to pin 4 of the 
vibrator EL Connect terminal 4 to pin 2 of 
vibrator EL Schematically the changes are 
shown in Fig. 3. This completes the equip- 
ment conversion. ( CO nL on page 103) 

BLACK- YELLOW 



RED- BLACK 




Fig, J, Jumper plugs. 



Fig. 3. Schematic of modification 



49 



73 MAGAZINE 



if.* 






* 



LOW COST 

ITAL CLOCKS 
& TIMER KITS 







Easy reading, 7 segment display tubes. Solid 
State MSI, IC electronic components. Accurate 60 
cycle line time reference, Simple, push button 
settings. Clock displays hours, minutes and 
seconds. 10 minute timer. 

Money back guarantee 

ORDER TODAY 
OR WRITE 
FOR DETAILS 



Clock kit: $74.50 
Timer kit: $54,50 

Add $10 for clock case 
$8 for timer case 



INTERPRISES 



506 Main St • El Segundo, Ca 90245 / 772-6176 



Fig. 4 m External power supply, 

The final step is to build the external 
power supply. Since this is to be a base 
power supply, it might be handy to build the 
power supply and the control head into a 
single unit. I will only show the power 
supply portion. The rest will be governed by 
imagination, pocketbook or your Fran's 
aesthetic desires. The major ingredients are 
the two 6V-18 amp transformers. The exter- 
nal power supply schematic is shown in Fig. 
4. The phasing of the 6V windings is 
important. When properly phased, the volt- 
age from point 1 to ground and point 2 to 
ground should be 6V, and the voltage from 
point 1 to point 2 should be 12V. 

. . .K0MOC 



REPEATER 

CIRCUITS 

MANUAL 



If you're into FM, you'll want to have 
this incredibly complete manual of FM 
circuits. You don't have your own repeat- 
er yet? Well, you've been thinking of 
it , . . admit it. Some fellows even have 
gone so far as to have a repeater in their 
car so they can extend the range of their 
hand units! 

This book, over 300 pages long, has 
just about every circuit that you could 
possibly want. Many of these have been 
published elsewhere, but many haven't, 
too. And you can go out of your mind 
trying to find a circuit when you want 
it ... so here they are, all in one handy 
place! 




,95 Hardbound, $4.95 Softbound 




73 Magazine 

Narnp 



Peterborough NH 03458 
Call 



i 



Address^ 



City, 



^ State 



-Zip- 



$6.95 hardbound, $4.95 softbound enclosed 

for FM Repeater Circuits Manual. 



50 



73 MAGAZINE 




James P. Wet, Jr. WB6BHI 
5002 Barstow Street 
San Diego CA 92117 




Base Operation 

the HR-2 Transceiver 



he Regency HR-2 Mobile Transceiver is 
a fine, high-quality piece of mobile 
2-meter FM gear. However, its "no-frills" 
design allows for quite a bit of individual 
leeway in the modification of the HR-2 for 
base station use. 



Power Supply 

Since the HR-2 operates from +12V dc, 
the first order of business is the design of a 
power converter between wall juice (117V 
ac and I 2 V dcJFigure 1 shows the schematic 
diagram of a supply designed to give 13.0V 
on transmit and 13.4V on receive. Tl is any 
transformer that will give 16 -19V ac out at 
2 amps. There are several companies 2 that 
make such transformers, or a 12.6V and 



6.3V filament transformer may be wired in 
series to give the required voltage. Diodes Dl 
through D4 form a full-wave bridge rectifier, 
CI is a 7000 /iF filter capacitor (1 used seven 
100 juF capacitors in parallel.) Any combina- 
tion yielding over 6000 juF of capacity 
should work to remove the ripple from the 
bridge rectifier. Q1—Q2 form a regulator- 
filter to regulate the +22 down to +13V. 
When the transceiver is on transmit, 25W is 
dissipated in Ql, so be sure to heat-sink it 
well. Q2 will draw a healthy slug of current 
under accidental short-circuit of the output, 
so heat-sink it well also, D5, D6 and the 
emitter-base junction of Q2 set the output 
voltage, and they must add up to the desired 
output voltage (12.0 + J + J = 13.4V 
output). Rl is used both as a surge-limiting 



no vac j- 1 

60 Hi /"K\ 



I 




110 VAC 
60 Hi 



ALTERNATE TRANSFORMER 
ISM Ttxt) 



IN400I 




Ql 
BN3055 



7000 uF 
TOTAL 
CI-C7 IN 
PARALLEL 
FOOO pF> 

50V to ffj 




CINCH/JONES 
S-304-CCT 






C9 

Z2 pF — 

25V /77 



_XD5 
Nibses 
J2V ZENER 



3 
I 
Z 

4 



02 
2N3055 



R4 

IOOa 
1/2 W 



| Fig. J, Ac power supply. Parts data -CI -C7: lOOOfJF 50V dc; C8: 5QQ/JF 50V dc; C9: 22flF 25V dc; 
D1—D4: IN40Q1 50 piv lamp; D5: IN963 zener diode, 12V; D6: IN914 silicon diode; II : neon panel 
lamp assembly; Fl: LA slo-blow fuse; Q1-Q2: 2N3448 or 2N3055; Rl : 0.5fi %W; R2-R3: IQOQSW; 
R4: J00n«W;TJ; 117V - 16 to 19Vat2A, 



APRIL 1972 



51 




EXISTING CIRCUITRY 



~l 



^T^CH6 +12 

/77 iR5_|OK 
r/4W 
WV 



R6-22 

I/4W 

CM 

,01 J/F 
50V 



r_ 



3 
l 

4 
2 



J 



fff fh 



ao 

.01 uF 

sov 




5O-0-5O 



Fig. 2. Installation of zeroing meter. Parts data — 
R5: 10 kfi S AW; R6: 22 k£2 14W; ClO-11: ,01 flF 
50V dc; Ml SO- 0- SO fiA panel meter, 

resistor and as a current-sensing resistor to 
he used later. Do not use a lower valve for 
C8 than 500 j^F, or the supply may oscillate 
and self-destruct Ql and Q2. Power connec- 
tions are made to pins 1 (ground) and 3 
(+12) of a female 4-pin Jones plug (note - 
the instruction manual shows pin 1 to be 
+ 12 and pin 3 to be ground - it might be 
wise to check the internal wiring of your 
HR-2 before you hook up the power cable. 
Mine was wired the opposite from the 
manual.) The extra pins (2 and 4 of the 
Jones power plug) will be used later as 
output to the zero-center meter 

Zero-Center Meter 

Another "frill" useful as a base station 
accessory is a meter in the discriminator 
circuit to detect the relative error of other 
stations or for "zeroing'* another transmitter 
frequency. Figure 2 shows how this modifi- 
cation is accomplished, IC 102 is the original 
discriminator, with output at pin 1 . Pin 2 is 





11 A 

— f=T\DS3 


Q3 / 


kj 


\ R7 




2N36381 


NOMINAL 








Rl 


i 




sc 


E FIGURE l) 






Fig, 3. "Transmitter On" light modification. Parts 
data - D7: 1N4Q01 diode; 12: 12V pilot bulb; Q3: 
DNP 2N3638; R7: 330U V 4 W nominal (see text); 
RL1: 12V relay. 



19-3/4 m 



1/4 m 0, GAS LINE 
COPPER TUBING 



! 

fr A *! 



MOUNTING FLANGE 
(ANY SIZE) 



DO NOT SHORT COAX 
BRAIO TO TUBING HERE 




SO-239 CONNfCTOfl 



PL -259 CONNECTOR 



8G-58/U ADAPTOR 



FLARE END SLIGHTLY 

3/6 in 0.0 GAS LINE 
COPPER TUBING 



RG-58/U COAXIAL 
CABLE (ANY LENGTH} 



Fig. 4. Fixed station antenna for $L 



a constant dc voltage representing zero 
frequency error. Pin 1 varies about this 
voltage plus or minus depending on whether 
the received frequency is high or low. 
Decoupling filters R5-CI0 and R6-C11 pro- 
vide the necessary isolation and meter multi- 
plication for a full-scale deflection of Ml at 
±25 kHz frequency error. 

Transmit Indicator 

Under certain circumstances, a ^trans- 
mit" indicator is useful. It may prevent 
inadvertent keying of the transmitter or a 
stuck microphone button putting out un- 
wanted Al emissions. 

Figure 3 shows the addition of the 3 parts 
to the power supply for this "transmitter 
on** light. When the current through Rl 
increases above an ampere or so, Q3 is 
turned "on," and provides current to lamp 
12, The current through the lamp is set by 
R7 to give a normal, above normal, or less 
than normal brilliance, Q3 is thermally 
adequate for the most normal operations, 



52 



73 MAGAZINE 



but you may wish to heat-sink the device or 
use a heftier device if you are particularly 
long-winded. A 12V relay (shown on the 
schematic inset) may be substituted in place 
of the light to control other functions, such 
as +12 to an external power amplifier, a 
110V light bulb, or other "power" devices. 

Antenna 

Since the use of the transceiver as a base 
station is an off-and-on thing, no great pains 
were taken to make the ultimate in gain or 
match with the base antenna. Figure 4 shows 
how a dollar's worth of goodies (except 
cable) makes a fairly respectable antenna 
with a resaonble vswr (less than L5: 1) across 
the 146-147 MHz band (less than 2:1 from 
144 — 148 MHz). Tuning is non-critical, and 
the gain is slightly superior to the more 
complex groundplane , The basic construc- 
tion is that of a coaxial sleeve monopole. 
One-eighth in. copper gas line is used for the 

radiating element and 3/8 in. gas line is used 
for the sleeve, These lines are available at 
your local auto parts house or "do-it-your- 
self ' handyman shop for about 25</ a foot. 
The S0239— PL259 are standard items at the 
local surplus shop or radio parts shop. 

Construction 

The photograph shows the completed 
base station. A 7x2x13 in. chassis was 
selected so that the transceiver could be set 
on it to form the base plate. The power 
supply components arc mounted in back of 
the transceiver on the chassis, and the 
underneath of the chassis is almost entirely 
taken up by filter capacitors. Figure 5 shows 
the drilling template I used to drill and 
punch the chassis. 






POWER POWER 






XISTOR XISTOR 






oe 




O0 


LINE COfiO 

® 

C 


8C OB 


XFMR 


BOOB 

°8 


GROMMET© 


Fuseff) 




r & _ ^ jl 










\_J l 

1 


u 




1 
1 
1 


1 


1 

1 

! | 


5.625 »n 




1 

i 




1 
I 








i 


E 


E 1 








! © Q 


^ 1 


! 


f 


J 1 




I 




hi II 


2.25 m. 

■ 




" . , . rn rJ 

1- -1 L J 1* -i 


1 




4 

ON-OFI 
9 PILOT 


,5 irv 


AO oa 


— 75 m 




METER 






LIGHT 





HOLE CHART 


SYM 


SIZE (DIAJ 


OTY 


A 


1/6 m 


2 


e 


J/4 in 


9 


c 


3/8 in. 


2 





1/2 in. 


1 


E 




4 



Fig. 5. Drilling template for home station adaptor. 



Layout and parts placement may vary 
widely from my design; there are no critical 
parts placement problems with a dc power 
supply such as this one* However, keep C8 
close to the base of Ql to avoid the 
aforementioned stability problems. 

Final Test 

Before plugging the transceiver in, load 
the power supply output with a 10O 1QW 
resistor and measure the dc voltage. It 
should be 13V ± the tolerance of your zener. 
No load voltage should be 13.4V ± the 
tolerance, A final check of the antenna vswr, 
and your excellent mobile rig is now an 
excellent base station also. 

/WB6B1JJ 



* * 



Completed unit 



References: 

L "Regency: An FM Late Starter/' Sessions 

K6MVH. 73 Magazine, p. 96, December 1970. 

2, Triad F60U ($7.68), Stancor RT~201 ($7.40). 

3. "Brew 1 on 2," Robinson WA0RWQ/6, 73 
Magazine, p. 86, September 1970. 



APRIL 1972 



53 




Versatility plus! ...in a 

2 Meter FM Transceiver 




Complete with: Dynamic Mike, 
O-T-S Carrying Case, 120 VAC 
and 12 VDC Cords, Speaker/ 
Headphone Plug and 10 Ni-Cad 
Batteries. 

$1QQ95 

I %# %# Amateur Net 

AA-22 Amplifier $149.95 

MM K-22 Mobile Mount $6.95 
BBLT-1440 Hustler Ant. $27.95 






Over-the-shoulder, mobile, or at home 

Completely transistorized, compact, portable. 
Capacity for 6 channels. Built-in telescoping 
antenna, and connector for external antenna. 
Use barefoot or with accessory amplifier. Ex- 
ternal 12 VDC or internal ni-cad batteries, 
built-in 120 VAC battery charger. 

GENERAL: • Freq. coverage: 144-148 MHz • 6 channels, 3 
supplied • Push-to-talk Xmit * DC Drain: Rev, 45 mA; 
Xmit, 450 mA • Size: 5-3/8" x 2-5/16" x 7-1/8", 3-3/4 lbs. 

RECEIVER: • Transistorized crystal-controlled superhet • 1st 
IF: 10.7 MHz, 2nd IF: 455 kHz* Ant. Input Imped: 50 ohms 
• Sensitivity: 1 fiV or less/20 dB S+N/N • Audio Output: 
0.7 W * Built-in speaker. 

TRANSMITTER • RF Output over 1 W • Freq. Dev. adj. to 
15 kHz max., factory set to 5 kHz. 












$®m 



wSK".-.'->::-:-'.v:' 



:■:•:->:•. 

"-■-'- r r p r t - 



. .:•:■:■:.■ 

■:■<><<■■ 



S^^^" : " : " : '-^v!'!'!v : ' : '-' : " : """""-'^''iv!'''!'!'!'I'! 






Wvm:;-:-. :-:-■-■-:-■-■-:-;- ■ • ■:■.*:■;■:■!■:-.■.• iommmm-Iv: >:•:■:■:•:-:-:-:-:■:■ 




Including transceiver, 3 
channels supplied, mobile 
mount, dynamic mike and 
built-in AC-DC power supply. 



'.-:-. 
.-.-.• 
--.-* 

M 



$ 





Amateur Net 






Accessory BBLT-144D Antenna: 
Hustler 14 dB gain $27.95 



EXCEPTIONAL QUALITY... 

VHF FM Transceiver 






GENERAL • Freq, coverage: 
144-148 MHz • 12 channels, 
3 supplied •Push-to-talk Xmit 
• AC drain: Rev, 6W; Xmit, 
50 W • DC drain: Rev, 0.5A; 
Xmit, 4A • Built-in Power 
Supply: AC, 117V 50-QO Hz; 
DC, 13.5V+10* • Size: 7-7/8" 
x 2-3/4" xltM/4", 8-1/4 lbs, 

TRANSMITTER: • Transistorized with 6360 output tube • 
RF Output: over 10 W • Freq. Dev: Adj. to 15 kHz max, • 
Freq. Stability: ±.001% or less • Output Imped: 50 ohms. 

RECEIVER: • Completely transistorized, crystal-controlled 
superhet • Intermed. Freq: 1st 10.7 MHz, 2nd 455 kHz • 
Input Imped: 50 to 75 ohms * Sensitivity: 0.5/iV or less/20 
dB quieting; 1/iV or less/30 dB S+N/N at 10 kHz dev,, 1 kHz 
mod. •Audio Output, 0.5 W • Spurious Sens,, >-60dB. 






R. L. DRAKE COMPANY 




DRAKE 



® 



540 Richard St., Mlamisburg, Ohio 45342 
Phone: (513) 866-2421 • Telex: 288-017 






The entries in this list are correct as nearly as we can 
manage right down to press time for this issue. Between 
indifference on the part of repeater managers and clubs 
toward getting their repeaters listed, a daily change in 
channels and the appearance of new repeaters on an almost 
daily basis, no list can ever be perfect. The list presented 
here is by far the most up to date available anywhere . . . 
and you merely have to keep tab on the repeater update 
column in the monthly 73 newspages ito dceep this list in 
near-perfect shape. 

We ask that you take it upon yourself to let us know at 
73 if you find any errors in the listings presented . . . or if 
you hear of any repeaters coming on the air that we do not 
have listed ... or any changing frequencies ... or going off 
the air. Send us a card, a QSL, a note, a letter, or even a 
radiogram via the traffic nets ... but send. The more 
accurate we can keep this list the more valuable it will be to 
everyone , . . and the more fun we will all have with 
FM > . . the Fun Mode. 



Repeater access methods are listed so; T1.95 means tone burst, 1950 Hz; 
W1.7, whistle-on center frequency 1700 Hz; TT, touchtone access (consult 
repeater club for access code); PL, private line (consult repeater club for exact 
frequency or reed number). Frequencies are listed so: figures in the last column 
{e,g„ 34—94) refer to the 146 MHz segment of the two meter band. If different 
segments are used in the input or output or both, frequencies are listed with UHF, 
six meter, ten meter or 220 MHz frequencies. 



APRIL 1972 



55 





ALABAMA 






K6MIA 

K6QF0 


Redding 

Redwood City TT.8 


145.22 

51.90 


147,20 

51.35 


















146.31 A 


146.49F 




WA4AHX 


Albertville 






34-94 
20-76 


WB6ZRR 
W6G0D 


Richmond 
Rio Linda 


146.40 


145.47 


JH— 3^ 


WB40EX 


Birmingham 






34-94 


WA6UGY 


Rio Linda CLOSED 








W4ZBA 


Demopolis W1.8 






34-94 


WA6JCW 


Sacramento 


146,? 


UHF 






W1.8 


52.76 


51525 








51.00 


UHF 








440.00 


449.00 




K4TXK/6 


Sacramento 


52.76 


52.525 




K4SPP 


Green Mt. 


146.94 


147.54 








52.76 


443.00 




K4IQU 


Huntsville T 






46-94 






52.525 


443.00 




WB4QEV 


Mobile 






34-94 


W6AQU 


Salinas 


146.60 


147.60 




W4JNB 


Muscle Shoals 






34-94 


WA6BTH 


San Bruno 


11.90 


51.35 




WB4QFR 


Phenix City W1.8 






28-B8 


WB60QS 


San Jose T2.4 


449.60 


444.60 


16-76 




ALASKA 






WA6UFE 
K6GWE 


San Jose 
San Rafael 






04-52 
10-70 
















448.25 


443.25 




— 


Anchorage 
Nome 






34-94 
34-94 


WA6UGM 

WB6IAG 

W6AEX 


San Rafael 

Santa Clara T2.55 
Suisan CLOSED 


145.1 0A 

51.00 

51.30 


146.70F 
51.00 
51.30 


34-94 




ARIZONA 






WBfiWYI 

K6JGE 


Vacaville T2.1 
Watsonville 


51.60 

146.928 


51.00 
147.60 




WA7HUH 


Globe CLOSED 


















WA7KUM 


Globe CLOSED 


















K7ZMA 


Kingman 






34-94 












WA7CEM 


Phoenrx 






34-94 1 

M ■■* *■» ■!■■ 


SOUTHERN CALIFORNIA 










16-76 












K7VDR 

rill ^tM flb J> ■ ■ 


Phoenix 


449.30 


445,30 


94-28 1 


K6SYU 


Anaheim 


145,62A 


1 45.49 F 


52-19 


W7AJU 


Prescotf 






34-84 


K6APE 


Bakersfield T1.7 


145,25 


146.75 












16-76 


WA6UJK 


Bakersfteld 


145,155 


146.90 




WA7KYT 
K7PQI 


Sierra Vista CLOSED 
Tucson 






34-34 


WB8SLR 


Blue Ridge 


146.94 
146.46 


449.15 
449.15 






ARKANSAS 










146.94 
146.46 


449.475 
449.475 














WA6FNT 


Crestline 






94-94 
76-76 


WA5YUT 


Ft, Smith 






34-94 










46-46 


W5ZF 


Hot Springs 






29-88 










34-34 


W5DI 


Little Rock 






34-94 


WB60PG 

K6SJF 

WB620I 

WGAOE 


Exeter T1.8 
T2.2 

Goleta 

Hollywood Hills 
Iriyllwild CLOSED 


145.20 
146.16 
146.61 


146.82 

146.995 

147.33 


16-76 


NORTHERN CALIFORNIA 


W6FND 
WA6CHZ 


Johnstone Peak 
La Crescenta 


145.15 


146.49 


82^70 


W6CX 


Alamo 


147.80 


147.06 














K6KDU 


Auburn CLOSED 








K6CPT 


Los Angeles 


145.66 


145.30 




W6TI 

WB60GJ 


Castro Valley 
Eureka 


147.96 


147.18 


34-94 


WA6FLH 


Los Angeles 


147.28A 
146.22 


145.30F 

147,39 




W86QVV 


Forest Hills T1.8 


51.60 


51.00 


W^T lJ jT 


K6MYK 


Los Angeles 

1 A M 


146.98A 


145.22A 




WB6HYL 


Fresno 






34-94 


WA6NUD 


Los Angeles 






34-94 






146 34 


52 525 


w~ Ln 


K6R0C 


Los Angeles CLOSED 


\ RACES 










52.525 


146.94 




WB6TXX 


Los Angeles 


224.82 


221.70 




W6JPU 


Fresno 


51.725 
146.12 


51,125 
147.71 




WA6UJS 


Los Angeles 


52.76 
52,525 


52.525 
449.95 








146.85 


147.71 




WA6UPB 


Los Angeles 


145.I7A 


147.66A 








448.00 


449.93 








22154 


146.66 




WA6RDY 


Fresno 


146.46 


147.84 




WA6ZOC 


Los Angeles 


224.82 


221.74 




WA6UGS 


Grass Valley T2.25 






34-94 


v Mm > &*m rf*. m m -k. .*— ^^i 




224.82 


146.40 




WA6ZDF 


Kentfield CLOSED 








WB6VYT 


las Angeles 


224.82 


146 40 




W6D00 


Los Altos 


146.85 


147.71 




WA6TD0 


Mt. Wilson 


145,425 A 


146.40A 




WB6LJR 


LosGatos CLOSED 








WA6ZNL 


Norwalk CLOSED 








WB6EMJ 


Merced 






06-76 


WB6GUA 


Palmdale T1.8 






34-94 


K6LY 


Monterey 






37-97 


WB6ZDN 


PalosVerdes CLOSED 






WB6ZDI 


North Highland 






16-76 


WA6URI 


Riverside 






16-88 


WA6RY0 


No, Sacramento 






80-20 


WA6LNU 


Saddle Peak 


221.63 


223.00A 




WB6AAE 


Oakland 

TU5 






20-80 
94-94 


WA6T1C 


Saddle Peak RTTY 






58-70 






449.50 


444.50 




WA6ALV 


San Bernardino TLB 






34-85 


WB6N0J 


Oakland T 


51.70 


51.075 




WB6WLV 


San Diego TZ.l.PL 






34-85 






50.40A 


51.07 








tht *J *. j_ J 


449.50 




WB6QE0 


Oakland CLOSED 








W6SD 


San Fernando Vlly 


440.50 


445.50 




K6SWS 


Oakland T1J 






34-94 


WBGTSO 


San Luis Obispo 






20-80 


K6YVY 


Droville 






34-94 


K6TAZ 


Santa Barbara 






34-94 


WA6TSM 


Palo Alto 


448.45 


443.45 


13-73 


WB6YZV 
W6FHF 


Santiago Peak CLOSED 
Santiago Peak CLOSED 






WAGYCZ 


Palo Alto CLOSED 








WB6ZRQ 


Sierra Peak CLOSED 








W6ECE 


Paradise 


147.00 


146.49 




WAGS IN 


Sulfur Mtn.T1.95 






28-88 


WB6SXC 


Petaluma 


145.98 
448,60 


146.90 
443.60 















56 



73 MAGAZINE 



CONSIDERABLY 

SPECIAL 

CONSIDERING 

THE 
SPECS 



NEW 2 METER FM TRANSCEIVER Model SRC* 146 

Frequency ** 143-149 MHz 

(2 MHz spread) 

Number of channels 5 

Supplied with 146-94 simplex. 

1 46. 3 4/- 94 (same plug in 

crystals as SR-C826M) 

R,F. Output...... ,.1 watt minimum 

Sensitivity...... .....better than 0,4 

uv/20 DB Q,S. 

Audio output,..., 500 mw 

Meter .monitors battery voltage on 

Tx, S Meter on Rx 

Current drain ♦•••...,. ...400 maTx, 

I5maRxSBY 
Size.,. ,.8%* high x 3" wide, x l%" deep 

Weight ..,..„ ,...„. ...24 oz., less 

batteries 

Options: external mie, or mic-speaken stubby flexible 
antenna, desk top charger, leather case, 






Suggested 
Amateur 
Net Price 




Consider the new VHF-FM hand held Transceiver by Standard Communications Corp,, with ex- 
clusive Astropoint design. For complete specifications and the name of your nearest dealer, write: 

STANDARD COMMUNICATIONS CORP. 

639 North Marine Avenue. Wilmington. California 90744.(213) 775-6284 



t^mm 



powerful performers ... 
reasonably priced ... 

high power 
fm amplifiers by Tempo 




A. TPL802 (SOW out) 
TPL1002-3 (120Wout) 

True powerhouses. 10W input gives a guaranteed 80 or 
120W output (In fact, typical output runs as high as 
140W), Operates directly from a 12 VDC power source. 
Antenna switching is automatic when as little as L5W of 
RF drive is applied. The amplifier incorporates Balanced 
Emitter transistors and state of the art design practices, 
making it virtually immune to destruction due to high 
VSWR or misloading conditions. Features include THREE 
40W output transistors (in the TPL10Q2-3) plus one 40W 
driver transistor, low loss input coax connector (complete 
with RF cable), low loss solid state antenna switch (.5 db 
or tess typical) and Spurious response: —60 db typ. All 
amps include a buift in power output monitor for use with 
a Remote Control Head and may be used anywhere in the 
2 meter band without the necessity of retiming. Only 9%" 
x 4%* x 3", theTPL1002 3 can be installed almost any- 
place. Since there are no switches or meters, it may be 
mounted under a seat, in the trunk or in a desk drawer. 
Power output: 120W. Input voltage: 13.8 VDC. Current 
required: 15-17 amps. Drive required: 5-25Wfor 100-140W 
out. Price TPL1002-3 $220.00 TPL802 $165.00 

B. TPL502 

A superior quality VHF FM two meter power amplifier. 
Only 6 l /z" * 3Vz" * 3", yet contains all the features of 
the TPL 1002-3 and provides a minimum of 45W output 
and typically 50W. Price $99.00 

The above amplifiers are completely compatible with the following 
transceivers: Tempo FMV & FMA / Standard 80S, 826 / Regency 



HR-2 / Rosswhite RWB / Telecom / Drake ML / Corncraft CTR 144 
/ Simpson Model A / Sonar 3601 / IC20. IC21 / or any other 
5 25W XCVR. 

Hi-power amps for handi-talkies & 1-3W xevrs 

C, TPL252-A2 

Unbelievably small ... but outperforms many of the big 
ones. 1-3W input delivers an easy 25W power output. 
Only $85,00 

A. TPL1002-3B (1-3W in/llOW out) 
TPL802B (1-3W in/80W out) 
TPL502B (1-3W in/45W out) 

Offering a variety of power inputs/outputs, but all with the 
same superb TPL features. 

The above amplifiers are completely compatible with the following 
transceivers: Tempo FMP / Standard 811 & Handi talkie / Motorola 
HT200 & HT220 /Drake TR22/ Sonar 2307/andany other IW 3W 
transceiver or handi -ta'kie within their frequency range 

UHF Power amps 



TPL445-30 

(4W in) 

TPL445-30B 
(1W in) 

1 or 4W input , . . minimum 30W output. 450 MHz UHF. 
Same features, . .same superior quafity as TPL 1002-3, 
including low loss solid state antenna switch. Ideal for 
use with 1 watt handi-talkie or other low power UHF 
transceivers. 




TEMPO OFFERS THE MOST COMPLETE LINE OF SOLID STATE AMPLIFIERS AVAILABLE 



MODEL 
NUMBER 



POWER 


POWER 


BAND PRICE 


INPUT 


OUTPUT (mini 






5 to 25W 


100-135W 


2M S 


£220.00 


1-3W 


SOW 


2M 


,235.00 


5W 


SOW 


2M 


5165.00 


1 to 3W 


80W 


2M * 


i 180.00 


5 to 1 5W 


35-55W 


2M t 


$ 99.00 


1 to 3W 


45W 


2M J 


5125.00 


1W 


25 W 


2M a 


> 85.00 


1 to 2,5W 


12W 


440MHz £ 


S125.00 


4W 


30W 


440MHz j 


(215.00 


1W 


30W 


440MHz ! 


5235.00 



TPL10Q2-3 

TPL1 002-3 B 

TPL802 

TPL802B 

TPL502 

TPL502B 

TPL252 A2 

TPL445-10 

TPL445 30 

TPL445-30B 



11240 W.Olympic Blvd., Los Angeles, Calif. 90064 213/477-6701 
931 N. Euclid. Anaheim, Calif. 92801 714/772-9200 

Butler, Missouri 64730 816/679-3127 



7 



58 



73 MAGAZINE 



they're both 
TEMPO... they're 



tit 



th 



value leaders 




TEMPO tm a 

The Tempo fma is the top of the Tempo VHF line. 
This transceiver offers all of the famous Tempo 
quality and performance at 25 watts of power output. 
The unit also features a low power position for 10 
watts output to conserve battery power. Here is a true 
value in VHF FM; Tempo presents high power 
operation for only $349,00. 




TEMPO imp 



The 3 watt portable from Tempo is the fmp. Truly 
mobile, the fmp gives amateurs 3 watts, or a battery 
saving % watt, FM talk power anyplace at anytime. 
With a leather carrying case included, this little 
transceiver will operate in the field, in a car, or a home 
with an accessory AC power supply. The battery pack 
is of course included. The price . , . $225.00. 

11240 W. Olympic Blvd. Los Angeles, Calif, 90054 

213/477-6701 
931 N. Euclid, Anaheim, Calif. 92801 714/772-9200 
Buffer, Missouri 64730 816/679-3127 



TEMPO . . . available from 
these select dealers 



HENRY RADIO 11240 W, Olympic Blvd., Los 
Angeles, Ca. 90064 477 6701 • 931 N. Euclid Ave,. 
Anaheim, Ca. 92801 772-9200 • Butler, Mo. 64730 
679-3127 

ADIRONDACK RADIO SUPPLY 185 W. Main St.. 

Amsterdam, New York 12010 842-8350 

ADIRONDACK RADIO & TV SERVICE Lewis. N.Y, 

12950, 873 2054 

ADVANCED ELECTRONICS 804 Dupont St., 
Bellingham, Wash. 98225 734-3400 

AMATEUR ELECTRONIC SUPPLY 4828 W. Fond 
du Lac, Milwaukee, Wis. 53216, 442-4200 ■ 
17929 Euclid Ave., Cleveland. Ohio 44112, 
486 7330 

AMATEUR RADIO CENTER 2805 N,E. 2nd St„ 
Miami, Florida 33137 374 4101 

AMATEUR RADtO SUPPLY 6213 13th Ave. $„ 
Seattle, Wash, 98108 767-3222 

BRISTOL RADIO ELECTRIC 420 Hope Street, 
Bristol. Rhode Island 02809,253-7105 

STAN BURGHARDT 315 10th Ave, N.W., 
Watertown, S.D. 57201 886-3767 

COMMUNICATIONS WORLD 4 788 State Road, 

Cleveland, Ohio 44109 398 6363 

DERRICK ELECTRONICS 108 E. El Paso, Broken 

Arrow, OMa 74012 251 9923 

DOUGLAS ELECTRONICS 1118 S. Staples, Corpus 

Christi, Texas 78404 883-5103 

ED JUGE ELECTRONICS, INC., 3850 S. Freeway, 

Fort Worth, Texas 761 10 926 5221 

ELECTRONIC CENTER 107 3rd Ave. N., 
Minneapolis, Minn. 55401 338-8461 

ELECTRONIC DISTRIBUTORS 1960 Peck St.. 
Muskegan, Mich 49441 726-3196 

ERICKSON COMMUNICATIONS 4657 N. 
Ravenswood, Chicago, III. 60640 334-3200 

ELECTRONIC EXCHANGE CO., INC. 608 Papworth 

Ave., Suite M B". Metairie, La. 70005. 834 9000 

FRECK RADIO & SUPPLY 3B Biltmore Ave,, 
Asheville, N.C. 28801 254-9551 

HARRISON Rt. 110 at Smith. Farmmgdale, N.Y. 
3 1735 293 7990 8 Barclay St., N.Y. City 227-7922 

HAM RADIO CENTER 8342 Olive Blvd,. St. Louis. 

Mo. 63132 993-6060 

HAM RADIO OUTLET 999 Howard Ave.. 
BurHngame, Ca, 94010 342-5757 

HIRSCH SALES CO. 219 Calif. Dr., Williamsvdle, 
N.Y. 14221 632-1189 

INDUSTRIAL DISTRIBUTORS 1209 S. Industrial 
Ave., Dallas, Texas 75207 742-8570 

JRS DISTRIBUTORS 646 W. Market St,. York, 
Perm. 17404 854-8624 

KASS ELECTRONICS 2502 Township Line Rd., 

Drexel Hill, Penn. 19026 449-2300 

LAND OF ELECTRONICS 400 S, Main, 
Lombard, ML 60148, 495-1234 

MADISON ELECTRONICS 1508 McKinney Ave., 
Houston, Texas 77002 224-2668 

PORTLAND RADIO SUPPLY 1234 S.W. Stark St., 
Portland. Or, 97205 228-8647 

RADIO COMMUNICATION CO, 10,000 Alkire 
St.. Arvada, Colo. 80002. 466-3000 

RADIO DISTRIBUTING CO. f INC. 1212 High St.. 
South Bend, Indiana 46624 288 4666 

RADIO, INC. 1000 S. Main, Tulsa, Okla 74119, 

587-9123 

RADIO SUPPLY & ENGINEERING CO, 85 Selden 

Ave., Detroit, Michigan 48201 831-3175 

SIMON SIDE BAND CO, Holland Mountain Road, 

Oak Ridge t NJ. 07438 697-4246 

WEBSTER RADIO 5755 E, Fountain Way, Fresno, 

CA 93727 291 6613 

WESTERN RADIO 1415 India St.. San Diego, Calif, 

92101 239-0361 

WORLD RADIO LABS 3415 W. Broadway, Council 

Bluffs. Iowa 51501 3281851 



APRIL 1972 



59 



WA6TTL Silver Pteak 



WB60PH Visalia 



WfllA 

WB0ERV 
WflJGL 
WA0BAG 
WBWYX 



WABIMVU 

K0QVQ 

WA0WC 

WA0VUD 

W0PRZ 

WA0SNO 

K0PHF 



WA1KHK 

WA1JTB 

W1NHK 

WA1KGB 
K1JGF 

WA1NOP 

WA1KGD 

W1COO 

WAIKGK 

W1CH 

WA1KHA 

WAIKGQ 



K3SVA 



WB4KVV 

W4IKB 

W4AB 

W84EQU 

WB4KLT 

WB4KNQ 

WB4HAA 

WB4GLK 

WB4QEL 
WB4QER 
WB4QEQ 
WB4IES 



WB4HAE 
W840EN 



52,525 


146.94 


146.94 


52.525 


51,336 


52,80 



COLORADO 



Boulder T1.8 

Buckhorn 
Castle Rock 
Colorado Springs 
Colorado Springs 



444.55 



449.55 



Denver 
Denver T1.8 
Denver 
Denver 
Grand Jet. 
Pueblo 

Pueblo 



5300 
444.45 
UHF 
146.82 

444,35 

145.32 



52.525 

449.45 

147.30 
449.35 

146.94 



CONNECTICUT 



Avon 

Bridgeport 

Columbia (CO) 

Farmingtan 

Grotan 

Naugatuck 

New Haven 

Ridgelield 

Trumbull 

Torrington 

Torrington 

Vernon 



145.47 

444,2 

441.85 

443,80 



52,76 



147,09 

449.2 

446,85 
448.80 



52.525 
448,3 



DELAWARE 



Delroar 



FLORIDA 

Boca Raton T 

Chipiey 

Ft, Lauderdale 

Ft. Walton Beach W1.8 29,44 

Ft, Walton Beach T1.8 

Merritt Island 

443.10 
Miami 

448.20 
Okeechobee 

Orlando 

Panama City W2.0 

Pensaeola T2.2 

St. Petersburg CLOSED 

Starke 

Tallahassee 

Tampa 



^9J4 



448 JO 
146.76 



Tampa 



448.20 
441.10 



146.76 
449,10 



GEORGIA 



W480C 


Atlanta 11. 8 


W4DOC 


Atlanta 


WB4NST 


Atlanta CLOSED 


WB4KLM 


Augusta 


W4V0 


Rome W 



34-94 



16-76 

25-85 
07-67 
16-76 
34-94 
16-76 



04^64 

34-94 
28—88 
28-88 



28-88 
31-88 

37-97 
19-94 

01-61 
16-7B 

25-85 

19-79 



22-82 



34-76 
34-94 
22-82 

34-76 
28-88 

34-76 

34-94 
94-76 
34-76 
34-76 
34-76 

34-94 
34-76 
34-76 



W4RRW Smyrna 



34-76 
22-82 

34-94 
34-94 
46-94 
28-88 



KH6EQF 



KH6EQR 
KH6EQK 
KH6EQL 
KH6F0X 
KH6NLH 



K7ZZL 



WA9EAW 

WA9WVA 

WA9GCK 

WA9DZ0 

WA9DZT 

WA9EAP 

WA90RC 



W9MJL 

WA9TEC 



WA9SGJ 

WA9EAT 

WA9EAE 

WB9AEF 

WA9EAM 

W9FBS 

W90GV 

W9YIY 

WA9WVB 

WA9LIV 

WB9HWS 

K9CLW 



WA9WVC 

W9ZPP 
WA9EAU 



W9INX 

WA9HRK 

K9LEH 

K9JSI 

W9C5F 

K9SJI 

WB9ADO 

W9EHZ 



WABVVD 

K0IXR 

WA0SNS 



WA0AMR 
K0OKI 



HAWAII 

Honolulu 

52.525 


20-80 
53.52 

444.15 



Lualuatei 

Wt. Haleakala 
Waiafua 

Waikiki 
Waipahu 



IDAHO 



Deer Point 
Orofino 



ILLINOIS 



Aurora CLOSED 
Batavia CLOSED 
Bloomington 
Chicago PL 
Chicago T1,8 
Chicago 

Chicago 
Chicago 
Chicago T1.8 

Danville 

Decatur W2.2 



52.76 52.64 

Mobile 147.46 147.75 

Base 147.50 147.75 



147.40 



W1.5 



WB9ADW Genoa 



146.34 
449.60 
146,28 
449.60 



Gray moot 

Jolret 

Oak Lawn CLOSED 

Peoria 
Petersburg 

Rockford 

Rock Island T1.8 

Troy 

Utbana 

Waukeegan 

Western Springs T2,Q 

Winnebago CLOSED 



146.28 



145.95 



INDIANA 



Anderson 
Evansville 
Ft, Wayne 



52.92 



Fl Wayne 

52.68 
Indianapolis 
Indianapolis 
La Porte 

Michigan City T 1.8 or PL 
Muncie T1.7 
Schereville CLOSED 
Schereville 



IOWA 



WA0VVA Cedar Rapids T2.0 



Council Bluffs 
Des Moines WT.2 
Waterloo 



146.34 
445.52 



KANSAS 



Kansas City 
Kansas City 



52.70 
52.38 
448,10 



147,81 



449.60 
146.90 
449.60 
146.88 



146.987 



146.55 



52.575 



53,88 



445.52 
146.94 



52.525 
52.525 
449.10 



16-94 
34-94 
20-80 
16-78 
16-76 



34-94 

34-94 



22-94 
10-85 



16-76 

34-88 
22^82 



13-76 
16-94 



34^76 
34-94 
82-94 
34-94 
34-76 
16-76 
34-76 

04-64 



22-82 

34-76 
34-94 

28-76 
28-88 

46-88 
34-76 
22-82 
31-97 
34-76 

34-91 



34-94 



22-82 
34-94 

34-94 



34-94 



60 



73 MAGAZINE 



With Apologies To The 

Crystal Manufacturers 

Of The World .. . 

Cfey? ANNOUNCES THE 
COMPLETELY SYNTHESIZED FM-27A 



2 METER FM 

WITH 80,000 FREQUENCY 

COMBINATIONS WITH NEVER 
A CRYSTAL TO PURCHASE 




FM-27A 

$449.95 Complete with Noise Cancelling 

Microphone and Antitheft Mobile Mount 



Only the FM-27A offers the 2 Meter FM'er the complete freedom of 
frequency— receive and transmit— with accuracy and stability comparable 
with conventional crystal control. 

In addition-the FM-27A provides the hottest performing receiver and most 
conservatively rated 25 watt transmitter on the market. 

See your Clegg Dealer today or write or phone our factory for detailed data 
sheet on the fabulous FM-27A. 



^mvfV-Ln 



W£MAWNAl 



£hssL 



DIVISION 



i> 



3050 Hempland Road 

Lancaster, Pennsylvania 17601 

Tel: (717)299-3671 • Telex 84-8438 



APRIL 1972 



61 



*^; ..111 J 



c 



2 METER "BLOCKBUSTER" 

180W P.E.P. SSB •150W DC input AM-FM uses a 
5894B twin tetrode • Built in AC supply — operate 
DC with Swan's Model 14C DC converter. Identical 
size and styling to Swan's SSB transceivers. Built-in 
antenna relay. Swan VHF-150 $279.00 
1 4C DC Converter , $65.00 



ew Swan FM 1210 



INDEPENDENT SELECTION 

of 1 2 transmit and 12 receive channels 

Comes with transmit — .22, .34, .76 and .94 

receive — # 28, .88 , ,76 and T 94 

Includes microphone, DC cord, AC supply. 



AVAILABLE NOW. 



m i a 



$329 



o-rv/-_: O 



. . rid lujj u 



*"•: . , . ¥ !WTT77. 



i«^^hy! 



r 

m 





SWAN FM-2X 



Extra xtals $3.95 ea 
installed free 



10 watts output • 12 channels 
Snap-on-the-back AC supply 
"Broadcast Quality" audio 
A truly outstanding value 



$259 



FACTORY-DIRECT" CASH PRICES 

24 HOUR SHIPMENT 

WE HONOR SWAN CREDIT PLAN 

ENTIRE SWAN LINE IN STOCK 



Send your check or money order or call in your 

order. Our phone is answered after hours automatically 

for your convenience. Call at night — cheaper rates. 

ED JUGE ELECTRONICS, INC. 

3850 SOUTH FREEWAY 
FORT WORTH, TEXAS 761 10 



Phone (817) 926-5221 



Hours: 9— 5:30 Tues. thru Sat 



62 



73 MAGAZINE 



7Q MAGAZINE 

III — <=?P> 



ISSUE 

EXCLUSIVE 

WARRANTY 



THIS MONTH ONLY . . . ON ALL SALES OF NEW FM EQUIPMENT DURING 
THE 73 MAGAZINE FM MONTH, JUGE ELECTRONICS WILL GIVE A FULL 
ONE-YEAR WARRANTY, WITH THREE OPTIONS: 

1. We will repair in our shop free of charge, any defective unit returned to us 
freight prepaid. 

2. Send your unit to the factory, prepaid, we'll pay their bill. 

3. Have ft repaired locally, send us the defective parts, and we will replace them 
to you. Sorry, we won't pay local labor charges. 

Place your order today. Please send cashier's check or money order ... for COD 
include 10% deposit. Mastercharge or Bankamericard accepted (send card number 
and expiration date. On Mastercharge send small "interbank" number shown above 
your name J AH in-stock items shipped the day your order reaches us. 

Urake TR-22 6-channel transceiver SI 99,95 Regency HR-2A T 5 watts out $229.00 

MMK-22 mounting bracket for TR-22 6.95 

AA 22 Xmit/Receive amp for TR-22 . . 149.95 

ML-2F Marker Luxury 12-channels 329.95 

Dy-Comm "C" amplifier $59.95 

"D" 10W in, 40-50 watts output 99.95 

E" 1-3W in, 20-30 wans output . . . . . 79.95 

"ES" 1-3W in, 40-50 watts output ........ 99.95 

"10-0" 10W in, 90-120 watts output 195.00 

Power supply runs 10-0 on AC . . . 75.00 



HR-2S base transcan 349,00 

HR-2MS mobile transcan 31 9.00 

Standard SRC-826M12-channels $339.95 

SRC-146 "talkie" . 279,95 

Swan see opposite page for prices 

Tempo FMA ....... $349.00 

Tempo FMP 225.00 

Tempo FMV .....*.* 249,00 



Crystals for Swan, Regency, Drake, Tempo .... 3.95 

Our own 4 Amp unregulated power supply for any above 10 or 15 watt rig. $19.95 

"JUGE" rhymes with "huge/' and that's the way we'd like to think of our service. 
We've been in the Amateur business now for eight years, and have built our 
reputation for service and assistance to our customers. Take advantage of this 
unusual offer ... we bet you'll become a regular Juge customer. 

ED JUGE ELECTRONICS, INC. 

3850 SOUTH FREEWAY 
FORT WORTH, TEXAS 761 10 



Phone: (817) 926*5221 



Hours: 9:00-5:30 Tues. thru Sat. 



APRIL 1972 



63 



WA0VVW 


Pittsburg 


WA0CJG 


Salina 


WA0SNP 


Topeka 


W0DKU 


Wichita 


W0IPB 


Wichita 



KENTUCKY 



W4M0P 

WB4RYX 

K4UCS 



Louisville 
Louisville 
Owensboro 



LOUISIANA 



WA5MZZ 

WA5ZHD 

W5WN 

WB5CDP 

W5MLE 



WB5AEG 
W5UK 



Alexandria 
Baton Rouge 
Lake Charles 
Monroe 
Morgan City 



New Orleans 
New Orleans W1.8 



52.827 

440.00 
444,50 
444,20 



52.525 

146.94 
52.525 

449.20 



MAINE 



W1QXR 

WA1KGP 

WA1KGZ 



Bangor 

Sanford 

Buckfield (Streaked Mt ,) 



MARYLAND 



WA3DZD Baltimore 



K3M0X 

WA3KW6 
W3UF 
WA3PPN 
WA3BMM 

K3SVA 

WA3PJQ 

WA3CJD 

WA3JCN 

WA3PVO 

WA3PVP 



Baltimore 
Cheverly 
Frederick 
Havre de Grace 
Rockville 

Salisbury 
Severn 
Silver Spring 
Silver Spring 
Stiver Spring 
Wheaton 



44B.10 
146.91 



449.10 

147.33 



53.25 
52.80 

146.46 
5276 

448.00 



223.30 
448.30 



52.68 
52.68 

147.06 
52.565 
449.00 



224.30 
449.30 



MASSACHUSETTS 



K1JMR 
WA1KEQ 
Wl RGG 
W1VAK 

K1AIU 
WA1KGR 

WIOFD 
K1FFK 

K1AOI 
W1CSF 



Boston 
Cape Cod 
Fall River 
Falmouth 
Framingham 
Holyoke 

Marlboro 
Ml GreyJock 

Oxford TT 
Pelham 



444.95 



449.95 



147.03 
5276 



W1BL 


Princeton 53.345 


W1RJS 


Salem 


WAIMHN 


Sornerville 


WA1KGS 


WaLtham 




444.05 


W1MTV 


WestfiGId 


WTHWK 


Weston 


WAIKRJ 


Worcester 




MICHIGAN 


W88CSC 


Ann Arbor 


WB8CSA 


Benton Harbor T2.4 


W8MAI 


Benton Harbor 


64 





147.87 

52.56 

50.50 



449.05 



M— 94 
34-94 
34-94 
34-94 
22-82 



34-94 
46-88 
34-94 



34-94 

34-94 
34-94 

34-94 



34-94 



34-94 
13-73 

M_Q£ 



22-82 
34 76 



0K61 

13-73 
25-85 



22-82 



19-67 
07-67 



07-67 
28—88 
34-94 
34-94 
34-94 

31-91 

28-88 
13-73 

28-88 
07-67 

04-64 

10-70 
22-82 
37-97 



37-97 
34-94 

22-82 



WA8BDD 

WB8CQS 

WB8CRK 

KBVLN 

WB8CRW 

WA8PUD 

K8TIW 

WB8CQM 

K8WNJ 

K8TJP 

K8WKE 



K0RTU 
WA0SSN 
WAGJCX 
W0CKF 



W0PZT 

WABCQG 

KBLAV 

WA0NPZ 

KflPML 

K0PMU 

WIUGR 

WA0CJU 



K5TYP 

WA5RMS 



WA0AMR 

K0FRA 

WABTEG 

WA0VUN 

WA0VVB 

W0OKB 

WABVVV 

WAflCJW 

KBRWU 



W7YB 
WA7KZF 



WA0MFU 

K0YRL 

W0EQU 



WA7HXO 
K7UGE 



Ciarkston 

Detroit 

Detroit 

Detroit 

East Tawas 

Grand Rapids T2.4 

Kalamazoo T2.1 

Lansing 

Muskegon 

Trenton 

Utica 



449.00 



444,00 



437.90 
43370 



442.90 
432.90 



MINNESOTA 



Duluth 

Elk River T1,8 

Faribault 

Minneapolis 

Minneapolis 



Minneapolis 

Rochester 

St Paul W1,4 

St. Paul 

St. Paul 

St. Paul T.18 

Waseca 

Waseca 
Wilmar 



53.64 
146.94 



146.46 
53.64 



146.58 



147,03 



MISSISSIPPI 



Bil0xi T2.0 
Gautier T2.4 



MISSOURI 



Kansas City 
Kansas City 
Kansas City 
Kansas City 
Kansas City 
Savannah 
Springfield 
St. Louis 
St. Louis 



MONTANA 



Bozeman 
Butte 



WA7QAA Gr:al Falls 



448.15 



449.15 



NEBRASKA 



Lincoln 
N. Platte 
Omaha 



NEVADA 



W7AKE Las Vegas 



147.18 
53.39 



147.84 
147.84 



Las Vegas 
Las Vegas 



31-85 
34-76 

46-64 

34-94 
34-94 
34-94 

22-82 



28-91 



34-94 
34-94 
16-76 
28-88 

94-46 



34-46 
94-46 

34-94 

34-76 
16-76 
94-46 

34-94 

J*l Jit- 

34-94 



34-94 
34-94 



16-7G 



52.70 


52.525 




52.88 


52,525 


22-82 

34-94 
10-94 

34-94 
34-94 


52.05 


5175 




441.56 


51.25 





34-94 
34-94 

34-94 



34-94 

34-94 
34-94 



20-80 



34-94 

40-94 
34-94 



73 MAGAZINE 



&c: 



Professional Quality for the Professional Amateur! 

AMATEUR- 2 meters 

TRANSMITTER-RECEIVER 

(from 144 to 148 MHz) 

COMPLETE FLEXIBILITY FOR MOBILE 

-BASE -HAND HELD 
PORTABLE 



'WhA. 



HAIHK>W IANDII 



- *" * 



Model FM 3601 (2 METER) 

• 8 Channels with Insiant Push Button switching * 10 Watts * 
Solid State, Finest quality silicon transistors • Netting trimmer 
for each receive and transmit crystal • High quality mechanical 
filter for adjacent channel rejection • Military-grade, glass-epoxy 
printed circuits ■ Rugged, serviceable design, compact construc- 
tion • Diode protected Dual-gate FET rni«er # 25 transistors, 1 
\C 1 MosFet. 16 Diodes • Overload protected receiver R.F. stage 



Complete with microphone, mobile mounting 
tray and 2 pair of crystals, (146.94T/146.94R and 146.34T/146.94R) 

Model PS-2923 AC Regulated Power Supply . . . $39.95 



SPECIFICATIONS 

Frequency Coverage: 144 — 148 MHz 
Dimensions: 6 3 4"Wx2*&"Hx9"D without tray 
Weight: 5 lbs. 

Microphone: Controlled Magnetic 
Antenna Impedance: 50 ohms 

RECEIVER 

Sensitivity: At feast 0.5 juV for 20 db Quieting, 

0.35 *jV for 12 db Sinad 
Selectivity; 16 KHz @ 3 db 
Freq, Tolerance: .001% from — 30'C to 60'C 
Spurious Rejection: At least 60 db 
Audio Power: 2 W. w'less than 10% distortion 
Squelch Range: 0.2 — 0.8 /iV 
Intermediate Freq.: 10.7 MHz & 455 KHz 

TRANSMITTER 

Emission; 16F3 (Frequency-Modulated) 

Frett, Tolerance; .0005% from — 30 5 C to 60°C 

RF Power Output: 10 Watts 

Spurious & Harmonic Attenuation; 

More than 50 db below RF carrier 
Deviation: Internally adjustable — 10 KHz 

POWER REQUIREMENTS 

Receive: Squelch standy: 0,175 Amp. 
Maximum audio: 0.500 Amp. 
Transmit: 1,90 Amperes 
Voltage; 13.8 VDC— Neg, Ground only 






^#JU^ 



11*** 



Plastic 1 
Case 



Model 2307 

VHF-FM (144-148 MHz) 

TRANSCEIVER 

5 CHANNELS 

HAND HELD PORTABLE 

* Provides immediate voice con- 
tact wilh Bate Stations, Mobile 
Units and other portable trans- 
ceivers • Compatible with ALL 
2-way communications systems 
■ Snap-in Nicad Battery Pack 
cartridge • Receiver and trans- 
mitter can be operated on inde- 
pendent frequencies • Electronic 
mode switching/no relays • Re- 
ceiver and transmitter sections 
are individual modules for easy 
servicing * Sensitive adjustable 
squelch * Sensitive, noise im- 
mune squelch • Meets all EIA 
requirements, 

complete with 
collapsible antenna 
and shoulder strap. 
Less crystals 5 battery cartridge* 



$ 450 



SPECIFICATIONS 

Frequency Range: 144-143 MHz 

Power Supply: Snap-In Nicad Battery Pack 

Power Drain: Standby — 10 ma 

Receive — 50 ma 

Transmit— 450 ma 
Battery Life: 8-14 hours 
Quick Charge: with 3 hours 
Dimensions: 3U"W x 9"H x 2D 

Weight: 1V2 lbs. 

TRANSMITTER 

Power Output: 1,6 Watts 

Modulation: ±5 KHz 

Stability -30 D C to +60°C: ±0.0005% 
Spurious & Harmonics: 46 db 
FM Noise @ ±3.3 KHz deviation: 46 db 
Audio Distortion: 10% 
Audio Response (EIA): 6 db per octave 
pre-emphasis from 300 Hz to 3 KHz 

RECEIVER 

Sensitivity: 12 db Sinad— 0.35 microvolts 

20 db Quieting— 0.50 microvolts 
Modulation Acceptance: ±5 KHz 
Spurious & Attenuation: 70 db 
Squelch Sensitivity: 0.15 microvolts 
Audio Output 65 ohm: 250 milliwatts 
Stability -30 C C to ^60°C: ±0.0005% 
Selectivity Adj. Chan,; 85 db 
Channel Spacing: 30 KHz 



SONAR RADIO CORPORATION 

73 Wortman Ave., Brooklyn, N.Y. 11207 



APRIL 1972 



65 




Been denying yourself all that great fun so 
many other amateurs are having with their 
rock-solid, through-the-repeater contacts? 

Delay no longer! Hasten to your SBE deal- 
er. Verify that the brilliant new SB-144 
has more channels-greater power output 
---starts your enjoyment now by including 
three sets of crystals on popular repeater 
frequencies and a high quality, SBE ex- 
clusive dynamic microphone without extra 
charge. Add a sizzling, double-conversion 
receiver and a combo "S" and output 
meter with big lighted scale that also saves 
your battery by showing when the trans- 
ceiver is ON, 

Confirm the price then make the deal. 
Lose no time in securing this book-size 
beauty under your dash with the tillable 
mounting bracket supplied. Then, power 
on! ENJOY! 



SB-144 



2 meter FM 

TRANSCEIVER 




Tenny Freck W4WL 

Harvey Nations W4VOV 

Sandy Jackson — Mgr. 

38 B ilt mo re Ave*, 

Asheville, N,C. 28801 

(704) 254-9551 



BEFORE YOU TRADE- TRY US! 

Bank Americard — Master Charge 
Two points to serve you 

FRECK RADIO SUPPLY 

Serving the area since 1928 




SCALE METER, 

COMBO, 

"S'VOUTPUT 



SUPPLIED 
WITH 


DYNAMIC 

Mfv. 







IN STOCK 



AT FRECK 



immediate 



Bill Ingram — Mgr. 

3008 Spring Garden St. 

Greensboro, N.C. 27405 

(919) 294-2311 



66 



73 MAGAZINE 



the new Swan 




1210-A 



IN STOCK AT FRECK 



for immediate delivery 





FM 1210-A 
SPECIFICATIONS 

• Frequency coverage 144—148 mc. 

• Number of channels: 144 (12 rev, 12 xmt, 
independent switching). 

• 8 crystals are included as follows: TRANSMIT: 
146.22, 146.34, 146.76, 146.94. RECEIVE: 
156.28, 146,88, 146.76, 146.94. 

• Modulation: frequency modulation (phase type). 

• Transmitter control: push to talk on micro- 
phone, 

• Power source: AC 117 volts 50-60 cycles, DC 
13.5 volts ±10%. 

• Dimensions: %V*" x 7" x 3". 

• Weight: 8% lbs. 

• Furnished with unit: dynamic microphone, an- 
tenna connector plug, spare fuses and lamps, AC 
power supply, DC power cord, and mobile 
mounting bracket. 

Transmitter 

• Fully solid state, no tubes. 

• RF output power: 10 watts nominal. 

• Frequency deviation: phase type, factory adjust- 
ed to 5 kHz. 

• Frequency stability: ±.001%, -30 to +50 C, 
oven controlled. 

• Spurious & harmonic radiation: —60 db mini- 
mum. 

• Frequency multiplication: 12. 

Receiver 

• Type: superheterodyne, dual conversion 16.9 
mHzand455 kHz IF. 

• Input impedance: 50 to 75 ohms. 

• Sensitivity: 0.5 uv for 20 db quieting, 0,25 mv 
for12dbSINAD. 

• Intermodulation: greater than 55 db. 

• Audio output: 2 watts at less than 10% distor- 
tion. 

• Image response: —55 db. 

• Squelch threshold: less than 0.3 mv. 

• Adjacent channel rejection: —55 db. 



Swan adds another dimension to 2 meter FM operation. 
Now with Swan's new independent switching for transmit 
and receive tuning (shown at right), combined with 
capacity for 12 receive and 12 transmit crystals, the FM 
1210-A provides the capability for 144 channel combina- 
tions. With this wide selection of channels, crowded 
frequencies and unwanted QRM are virtually eliminated. 

Selectivity has been greatly improved with the addition 
of our 16.9 mc crystal lattice filter that provides substan- 
tially greater rejection of adjacent channel interference. 
Extensive testing has shown that the new Swan 1210-A has 
selectivity equal to any 2 meter transceiver on the market, 
at any price. 

The power of the FM 1210-A is rated at 10 watts output 
which, with the proper antenna, provides you with reliable 
communications. The output transistor is protected against 
damage from an improper load by an automatic protection 
circuit. 

Each crystal has its own trimmer capacitor for exact 
frequency adjustment, In addition, the FM-1210-A is the 
ONLY 2 meter transceiver to provide a crystal oven for 
superior stability on those cold mornings. 

Receiver audio to internal speaker is rated at 2 watts, 
almost twice that of most other 2 meter units, for loud 
clear reception of the station you are working. Provision 
has been made for the addition of an external speaker, and 
there is external keying for an amplifier. 

As little as $10 per mo. on Swan's new 
Revolving Credit Service thru Freck. 

$26 down, $10 mo. on unpaid balance. Annual per- 
centage rate 18%. 

BEFORE YOU TRADE - TRY US! 

Bank Americard — Master Charge 

FRECK RADIO SUPPLY 

Two points to serve you 



Tenny Freck W4WL 

Harvey Nations W4VOV 

Sandy Jackson — Mgr* 

38 Biltmore Ave., 

Asheville, NX. 28801 

(704) 254 9551 



Bill Ingram — Afgr. 

3008 Spring Garden St. 

Greensboro, N.C. 27405 

(9191 294-2311 



Serving the area since 1928 



APRIL 1972 



67 





W7CX 
WA7NHV 


Reno 
Reno 


147.85 

UHF 

147,00 


UHF 
146.20 

146.94 


34-94 


W2GHR 
WA2PDJ 


Hunter Mt. 
Huntington LI 






28-88 

28-91 

28-85 
25-85 




K7TNU 


Reno 


146.94 


5T.60 




WA2UZE 


Huntington LI 






52-76 








51.0 


146.94 




WA2BXK 


Hyde Park 


441.00 


446.00 






K7UGT 


Reno T2.4 


146.94 


147.48 


34-94 


W2CXM 

WA2UWK 


Ithaca 
Jamestown 






34-94 
34-94 




K7VJZ 


Reno 


146.94 


52.525 




■ Ad i^ fa d . n« 








28-88 








52.525 


146.94 




W2WJS 


Long Island 


441.65 


446.65 


<*_. w UU 






NEW HAMPSHIRE 




WA2UYP 
W2DQI 


Mt, Beacon 
Manorvflfe LI T 


441.15 


446.15 


34-82 



W1ALE 



K1MNS 
WA1KFV 

WATKGO 
WA1KGU 



W2KUU 
W2BHK 

K2JEZ 
WA2UWC 

WB2KK0 
WA2UWR 

K2GE 
W2FLY 

K2TYV/2 



WA2ZVQ 
W2SJT 
WA2PRI 
K20DP 



W2DRZ 

WA2CKW 

K2LDT 

W2TFJ 

K2KDA 
WB2TLJ 



W2S8 

WA2UYI 

WA2UYJ 

W30EG 

K2KOA 



Concord 

Except 1st 3 milt of each 15: 

146.46 146.94 

146.46 52.525 

52.525 146.94 

Derry 

Manchester CLOSED 

Peterborough 
Salem 

NEW JERSEY 



Camden 
Cherry Hill 

Fords 447.40 

Greenbrook 

Oakland 

Paramos PL 4A 14L3 Hz 

449.10 

Sayerville 

South Jersey 

Split Rock 

444 Q 

146.4 

444.9 



449.40 



448.10 



Toms River 
Washington 
W. Orange 

Woodbridge PL 



443.25 



449.9 
449 J 
146,97 



448.25 



NEW MEXICO 



WA5KUI 


Alamagordo 


K5CQH 


Albuquerque 


WA5JDZ 


Albuquerque 


WA50IP 


Albuquerque 


WA50XB 


Albuquerque 


WA5QLZ 


Albuquerque 




Las Cruces 


W5PDO 


Los Alamos 


WA5YTG 


Porta les 


WA5DMQ 


Roswell 


K5SFB 


Sandia Crest 


WA5VKY 


Sandia Crest 


WA5YTK 


Sierra Blanca 



146.46 



146.40 



146.46 



147.06 



147.00 



147.06 



448,60 
146.46 
145.50 



443.60 
147.06 
146.50 



NEW YORK 



Bath 
Birch Hill 

Boston 

Bfookhaven 

Brooklyn 
Buffalo 



WA2UY0 Cherry Creek 



Dunkirk 
Farmingdale Lf 
Gore Mt. 
Grafton 

Hemostead LI 



145.20 

53,60 
50,74 

441.55 

On request 

146,34 

441.75 
441J5 

441.70 



147 J 2 



146,82 
146.82 

446.55 



146,147 

446.75 
446, T 5 

446.70 



34-94 



25-85 

19-79 
37-97 



25-85 
22-82 

34-94 
37-37 

15-91 
19-79 

16-46 
22-82 
40-97 



31-91 
22-82 

22-82 



34-94 

34-94 
25-88 

28-88 

34-94 

34-94 
34-94 
34-94 



58-94 

31-91 
34-94 



31—91 

34-94 
31-91 

34-94 



22-76 



YVA2UVX 

WA2SUR 

K2UHD 

WA2INM 

K2KDA 

W2CVT 

WA2UWQ 
W2IBW 
K2AE 
WA2YYQ 

WA2YZZ 
WA2UWF 

K2DHH 
WB2NMZ 

K2GVI 

WA2UWS 

K2AVP 



WA2UYJ 

K2LJC 

WB2BLQ 



146.34 
147.00 

147,12 
146,205 

441,80 

441.15 
Rochester 

Rockland Cty CLOSED UHF 

Schenectady 

Stater* Island 

Staten Island RTTY 449.25 

Syracuse 



Millbrook 
New York City 
New York City 
New York City 
Plainview LI 
Poughkeepsie 



147.12 
147.69 

147.68 
146.805 

446.80 
446.15 



13-73 



Troy 
Troy 

Utica 
Utica 
Westchester 



Wrmeface Mt. 
Wood mere LI 
Yonkers PL4A 



53.75 
53.75 

53.75 



146.46 
(CD I 15 
(CD) 145,68 



31-91 



146.70 

52.64 
52.58 

52.58 



147.06 



147.06 



37-97 

28-88 

46-94 
28-88 

46-94 



34-94 

34-94 
28-88 



22-82 

04-64 



NORTH CAROLINA 



WA4NU0 
WA4UMH 
K4RSH 

W4BFB 

WB4QFT 

K4RUQ 

WA4VTX 

W4NBR 

WB40FF 

K4VUG 

W4PAR 

WB4NXE 



W4DCD 



Asheville 

BeuJaville 

Chapel Hill 

Charlotte 

Charlotte 

Durham 

Durham W 

Elizabeth City 

Goldshoro/Kinston 

Greensboro 

High Point 

Lexington 

Mt. Airy 

McCain 



N. Wilkesboro 



444.25 



•U9.10 



WA4EHL Raleigh 



K4ITL 
WB4PPS 

W4EXU 
W4NYR 



Raleigh 
Roaring Gap 
Salisbury 
Shelby 



52.525 

52.78 

146.42 

52.78 

146.42 

52.525 

52.780 

146.42 

52.525 



146.05 
52.525 
52.525 

52.525 
52.525 
146,05 
52.525 
52,525 
146.05 



34-94 
34-94 
22-82 
16-76 
34-94 

34-94 
28-88 
16-76 

16-76 
34-94 
31-91 

38-98 



28-88 
22-82 
28-88 

28-88 



NORTH DAKOTA 



WA0VVZ Eckman 



34-94 



OHIO 



K8HRS 
WB8CRS 
W8AIC 
W8ERD 



Ashtabula 
Cincinnati T1,8 
Columbus 
Columbus 



29.50A 
50.54A 



146.82F 
146.82F 



34-76 
34-94 
34-76 



68 



73 MAGAZINE 



■I 

meter FM 

Mobility at 
unheard-of 



Sa vings 



1 I *W > 



• 



t _ 



AVCOM 
FM-201 
SOLID STA TE " 
TRANSMITTER 
MODULE 

Starts You on Your Way! 

Only ^AQ .95 COMPLETE -Not a Kit 



90-Day Warranty 



(deal for Repeater use! Just add ant, 
mike, Xtal and 12-16 volts DC. 

Cut Transceiver cost as much as 50%. 
Add police band receiver to AVCOM FM-201 
Transmitter. Your rig can cost under 
$100 while others are priced up to $250, 

Already have a 2 Meter FM rig? Increase 
your fun, save installations and removals 
of your high priced mobile rig with a 
low-cost second rig. 

Walkie-Talkie compactness — glass epoxy 
printed circuit board is only 3" x 3Vi". 



SPECIFICATIONS: 

Mike Pre-Amp: high impedance 
input, integrated circuit. 

Operates anywhere between 12 
and IB volts DC. 

4.0 kHZ frequency deviation 
typical. 1 -Watt DC input to 
final transistor 



Order Your FM-201 Transmitter Module Today! 
LM-210 10 Watt POWER Amplifier Module $29.95 

AVCOM, Inc. 

P.O. BOX 29153 COLUMBUS, OHIO 43229 



APRIL 1972 



69 



■^^^ 



MP 





2 METER 

ANTENNAS 

Complete stock of Fft/I 
Antennas for base or 
mobile 

Large drive-in on the 
premises for immediate 
installation or service 
Complete line of Motor- 
ola H.E.P. transistors at 
all times 

by 




rush 




CORPORATION 



WE CARRY 
STANDARD 

E. T. CLEGG 
GALAXY 

REGENCY 
DYCOMM 

DRAKE 

CUSH CRAFT 

HY-GAIIM 

ANTENNA SPECIALISTS 

SONAR 

MOSLEY 

ROHN TOWERS 



and see the largest 
stock of new and 
used ham gear on 
the East Coast. 



P.S. - We 

will trade any 

kind of electronic gear 



NEW 2 METER FM TRANSCEIVER 



Model SRC- 146 




$279 



by 

STANDARD 

COMMUNICATIONS 



Credit cards honored — 

Mastercharge, Bank Americard, 

PNB,GEC,etc. 

We ship anywhere in USA 

via UPS - NO CHARGE 

TO YOU 



4033 BROWNSVILLE RD., TREVOSE. PA. 19047 



70 



73 MAGAZINE 




Over $5,000 crystal inventory, all standard frequencies in stock. 
Complete lab set-up, Cushman E-3 counter and deviation scope. 
Every set sold checked out by our FM experts. 
Put precisely on your frequency before snipping to you at no charge 



MODEL 

TR-22 



$199.95 



meter 



Transceiver 




RECEIVE ANY FREQUENCY IN THE 2M BAND 
146-147 MHz) WITH 2 SIMPLE SETTINGS 

ON THE NEWCLEGG 

FM-27A MOBILE 




DIVISION 



Stop in and browse at FM HEADQUARTERS. 

use — Frequency Counter in our showroom wi 
and check your own frequency. 



Free coffee and donuts. FREE — for your 
ow runs 24 hours a day. PuU up in front 



(215)357-1400 



PHONES 



(215) 757-5300 



APRIL 1972 



71 



W8WTB 


Cofumbus 






34-76 


K3GKB 


Honeybrook 






13-73 


W68CQR 


Cleveland PL 






34-76 


WA3BK0 


Philadelphia 






28-88 


WB8CRV 


Cleveland CLOSED 
















<*p %P Iff w 

1G-7G 


WB8CQK 


Dayton T 






34-94 










1 V f u 

34-94 


W8QLS 

A ■ ■ ik ^m, ^k m^ 


Delaware 


145 .62 


146.85 


37-97 


WA3KUR 


Philadelphia 


446.60 


449.60 


34-76 
31-91 


WB8CRL 


Fletcher 






46-88 




r 


52.72 


52.64 




WA8WMH 


Hamilton 






37-97 






52.76 


52.60 




WA8PLZ 


Miamisburg 






22-82 






448.80 


443.80 






TT 


448 JO 


146.82 




WA3QCE 


Pittsburgh 






34-76 


K8PWL 

1 A. P 1*1 J1 «F% P^ I I 


Miamisburg 






22-88 


W3BN 


Reading 


52.575 


52.680 


*mW P ■ U 


WB8CRU 
K8JHG 


Newcomerstown 
Ottawa 


■v Mm m*. m 




34-76 
28-88 


W3CCH 


Reading 
Scran ton 


51.575 


52.64 


34-94 






52,76 


52.525 




WA3JPP 


Sellersville 






28-76 


KSZPR 

WBSCQO 


W1.8 

Steubenville 
Toledo 


53.36 
52.76 


53.54 
53.54 


34-76 | 
34-76 


WA3KUW 
K3PQZ 


State College 
York 


446.50 


449.50 


34-76 

34-76 

34-76 


- — 


Troy 






46-88 






■ 






W8100 


Youngstown 


Mobile 




34-76 
















Base 




31-76 




RHODE ISLAND 














K10HE 


Bristol 






34-94 




OKLAHOMA 


i 




K1ABR 
W1HQV 


Providence 
Woonsocket 






10-70 
16-76 


*— 


Ardmort 






34-94 












WA5LDJ 


Bartlesville 


52.525 


146.94 


34-94 












WA5MQA 


Cherokee 

Chic kasha 


T46.94F 


145.96A 


34-94 


< 


SOUTH CAROLINA 












37-97 












WA5YUH 
WA5QYE 

K5CEM 
WA5YTI 


Ourant 

Enid 

Oklahoma City 
Oklahoma City 


449.45 

449.00 


444.45 

447.00 


34-94 
34-94 

22-82 
34-94 


WB4QGK 

WA4MPC 
WB4PLN 

WB4PUP 


Charleston TT 1447 Hz 

Columbia 

Columbia 

52J6 
Greenville 


52.525 


28-88 

34-94 

28-88 


WA5ZZA 
WA5LVT 


Oklahoma City 
Ponca City 
Tulsa 


52.68 


5^525 


16-76 
34-94 
34-94 

28 -M 


WA4SSJ 


Greenville 


52.76 
52.76 


52.525 

52.525 


34-94 


WA5SJE 


Tulsa 


449,10 


444.10 


22-82 




SOUTH DAKOTA 














W8BX0 


Brookings T2.1 






34-94 




.-^fek. 1^1^^^ i^^» ■ — 








WAflVVG 


Sioux Falls T1.8 






34-94 




OREGON 














** «■ *+ T 


W7DBS 


Eugene 






34-94 












— 


King Mt. 
La Grande 






34-94 
34-76 




TENNESSEE 






W7FIO 


Lookout Ml 






34-94 
















52.92 


53.46 




WB4KL0 


Chattanooga 






34-94 


— 


Mary's Peak T2.25 






34-94 


K4HXD 


Knoxvitte 






34-94 


W70FY 


Medford T2.4 






34-94 










38-94 


• - 


Newport 






76-94 






146.34 


440.60 




— 


Pendleton 






34-94 






146.38 


440:60 




K7DVK 


Portland 


447 J 7 


449. T7 




K4RSV 


Lenoir City 


146.46 


147.06 




K7SJQ 


Portland 


444.17 


449.17 




W4BS 


Memphis 






22-76 


W7VS 


Portland T2.1 


* 




34-94 


W4CV 
W4AY 
WB4QEY 
W4RFR 


Memphis 
Nashville 
Nashville 
Nashville 


440.00 
146.04 


449.00 
147.18 


34-94 
10-64 

34-94 




PENNSYLVANIA 




WA4YND 


Nashville 
Oak Ridge 


146.70 


147.70 


28-88 












W4IWV 


She I by vi He 






34-94 


W30I 


Al lento wn 






34-94 1 








-r 




WA3IGS 


Berwyn 


52.80 


52.72 


28-76 




TEXAS 






W30K 


Bethlehem 






16-70 












W3VV 


Bradford 






34-94 


■ — 


Abilene 






34-94 










25-85 


— 


Alice 


444,10 


449.10 




K3ZTP 


CoatwiNe 






22-82 


W5CBT 


Amarillo 






34-94 


K3DSM 


Devon 445.90 


448.90 






K6F0G 


Arlington 


53.05 


53.15 




WA3KUV 


Erie 






19-79 






UHF 


I 




WA3MOP 


Erie 


449.55 


444.55 




W5NEC 


Austin 






34-94 


WA3ICC 


Harrisburg 






34-76 


WASYTO 


Austin 


449.10 


444.10 




WA3KWI 


Philadelphia 


449.00 


444.00 




W5AW 


Big Spring 






34-94 


vwav 


Philadelphia AM 


29.64 


29.493 




WA5YTJ 


Corpus Chrisii 






34-94 


W3SK 


Philadelphia 






37-97 


WA5HNW 


Dallas 


53.55 


52.95 




72 














73 MAGAZINE 



WA5VKV 


Dallas 


WA5VKW 


Dallas 


W5HHS 


Denton 


WA5MWI 


Ft, Smith 


K5DSV 


Ft. Worth 


WA5KT0 


Ft. Worth 


WA5YTM 


Ft. Worth 


V^BB 


Ft. Worth 


WA5QLA 


Houston 


WA5QT2 


Houston 


WA5YUB 


Houston 


WA5YTY 


Killeen 


WA5YUP 


Longview 


WB5BRY 


Lubbock 


W5QGG 


Midland 


WA5SNJ 


Pasadena 


W5YNL 


Ptainview 


WA5YUS 


Port Arthur 


W5UF0 


San Angelo 


WA5UNH 


San Antonio 


WA5VKZ 


San Antonio 



449,00 



444.00 



WA5LDL 



WA7GTU 
WA7AKI 



WB4QFP 

WB4KNX 

K40QS 

WB4QEP 

WB4KNU 

W4GCE 

WB4HCX 

WB40RI 

WB4URR 

WB4KNN 

W4DXC 

W4NJE 



WB4QE0 
WA4V0S 



WA7KGV 
WA7KZG 



W7DAQ 



W7QKL 

WA7KYY 
K7IUT 

W7FH2 
K7PBU 



448.90 
53.05 



441.10 



52.88 
UHF 



Tyler 



UTAH 



Cedar City 
Salt Lake City 



444.90 



VERMONT 



WA1KGM 


Mt. Ascutney 




WIAfil 


Killington 


441 .20 


W1KQ0 


Mt. Mansfield 


444.40 



VIRGINIA 



Arlington 

Charlottesville 

Chesapeake 

Danville 

Hampton 

Lynchburg 

Lynchburg 

Manassas 

Manassas W2.5 

Newport News 

Richmond 

Richmond 



Richmond W1-4 
Richmond 



H6.22 

52.78 
37-97 

52,72 
146.22 
146.22 
52.64 



53J25 
443.90 

53.15 



449.10 



52,525 



449.90 



446J0 
449.40 



147.42 
52.525 



52.640 

147.42 

52.64 

147,42 



WASHINGTON 



BawfawMt. T1.95 
Ctiehalis TT.95 

Ephrata 
Longview 

Moses Lake 
Mt. Rainier 

Mt, Spokane 

Olympic 

Puget Sound CLOSED 

Puget Sound 



53.29 
J4676 



146.76 
53.29 



52,525 

449.85 



53.29 

444.85 



28-88 
25-85 
34-94 

16-76 

34-94 



28- 

22-82 

16-76 

0*|— "^ 

28-88 

34-94 
34-94 
34-94 

22-82 
22-94 

34-94 
34-94 

34-94 

34-94 





WA9ZEF 


Appleton T1.8 


Id 04 


W9AYR 


Green Bay 


34-34 


WA9PBW 


Madisoq T2.1 




WA9WVE 


Madison T2.Q 




W9R0M 


Milwaukee T 




W9AIQ 


Sturgeon Bay T1.8 




1 WA9LIV 


Waukegan 


16-76 






28-88 







34-94 



31-91 
28-88 
22-76 
28-88 
34-94 

34-94 



34-94 



34-94 

28-88 



34-94 

34-94 

34-94 



34-94 

34-76 
34-94 
34-94 



W7DXX 

W7DSF 

K7GMR 

W7PUG 

K7LBV 

K7PYC 

WA7AJF 



Rattlesnake Mt. 

Seattle CLOSED 

Seattle 

Seattle 

Spokane 

Tumwater 

Vancouver 

Wenatchee 
Yakima 



52.525 

52.525 
52.525 
52.92 



53.29 

53.29 

5329 
53,46 



WEST VIRGINIA 



WB8ARY 


Huntington 


K8SX0 


Huntington 


K8BOT 


Parkersburg 


K82PR 


Weirton 


W8JDJ 


Wheeling 



WISCONSIN 



WYOMING 



K7KMT 

WA70TP 
WA7KZC 



Casper 

Casper 
Laramie 



444.55 



444.30 



449.55 



449.30 



WA7EGK Laramie 



K7SDD 
W7RPV 



Laramie 
Worland 



CANADA 



ALBERTA 



VE6AUY 

VE6WQ 
VE6W0 
VE60L 



Calgary 

Edmonton 

Edmonton 

Grand Prairie 
Lethbridge 
Red Deer 



146.46 
146.46 
146.46 

146.46 



147.00 
147.33 

147.00 
147.00 



BRITISH COLUMBIA 



34-58 



88-58 



34-94 
34-94 



34-76 

34-76 
34-76 
34-76 

34-76 



34-76 
28-88 

34-76 
46-88 

34-76 
34-76 



34-94 

34-94 
16-76 

34-94 
76-94 

16-76 
34-94 



34-94 



34-94 



VE7ELK 


Chilliwick 


146.46 
147.33 


147.00 
146.58 




_*. 


Kamloops 






34-94 


VE7CAP 


Kimberly 






34-94 


VE78TU 


Nelson 
Penticton 


146.46 


147.33 


34-94 


VE7AFG 


Prince George 


146.58 


147.33 





APRIL 1972 



73 



high performance bo/e loaded 
2-meter fm mobile antenna 

Model ARD-150 is an easily mounted 5 /a wave mobile antenna with 
3 db gain. Produces increased range and better mobile to mobile 
or mobile to base communications. 

Durably constructed to give long lasting performance, all fittings 
are triple chrome plated brass or stainless steel and the coil is 
hermetically sealed in A.B.S. to prevent detuning due to moisture 
or corrosive atmosphere. 

Comes complete with built-in heavy duty V2" snap mount (Vb" 
available at no extra charge) and 20' of coax. 

In addition to the regular mechanical inspection, each ARD- 
150 is 100% tested for V.S.W.R and "0" before shipping. 

1 year guarantee. If any defect occurs mechanically or electrically, 

we will replace or repair your ARD-150 at no charge. 



SPECIFICATIONS 



$26.95 



Frequency — Field 
tunable 140-175 MHz 
V.S W R-— 1 3 1 or better 
Impedance — 50-52 ohms 
Gain — 3 db 



Radiator— 17-7 PH 
stainless steel 
Spring — stainless steel 
Whip Length- 
Max 48", Mm 36 r 



-%\|*-^VV%m 33-35 WEST FULLERTON AVENUE. 

#W#\l\m% ADDISON, ILLINOIS 60101 

AVANTI RESEARCH & DEVELOPMENT, INC. 

We also have a complete line of high performance base antennas. 





NEW CONCEPT... 

in 2 METER FM OMNI 



Again, Out of research comes increased performance. AvantTs unique 
ARD-257 2-meter FM omni is engineered to give you more gain and all 
around higher performance than any other anienna of its type or price. The 
patented tapered skirt configuration produces 4. 1 7 db gain (measured over 
l /x wave ground plane) plus a low angle of radiation thai has proved effec- 
tive in eliminating dead spots. Nocoikor transformers to detune or burnout 
. . . unaffected by temperature and humidity, The small projected area and 
light weight provides easv mounting and gives wind survival to 1 20 MPI-L 

Construe! ion is all aircraft Quality aluminum and hherglass. Antenna 
comes complete with coax lead, mounting hardware and fiberglass mast 
current eliminator, 

Other frequencies from 140- 1 "\s Mil/ are available upon specification. 



SPECIFICATIONS: 



Gain — 4.17 db 
V.S.W.R.— 1.5:1 or less 
Bandwidth— ±3.5 MH/ 
Impedance*— 50*52 ohms 



Power Mandl i nu — 
1000 watts 

Polarization— Vertical 

Connector— PL-259 



$4495 



33-35 WEST FULLERTON AVENUE, 
t ADDISON, ILLINOIS 60101 

AVANTI RESEARCH & DEVELOPMENT, INC. 

We also have a complete line of high performance mobile antennas. 



74 



73 MAGAZINE 




from Ross and White 

The 1st 2 meter 
FM transceiver 

with a built-in tone burst 
encoder 



12 channel capability 

4 crystals installed. 



Tone burst 
encoder built-in 
with 3 tones variable 
from 1600 to 2400 Hz 



All the Quality performance and flexibility 
that hams want and need for all-around 
2 meter FM repeater operation. 

All solid state design — no tubes. 

Individually performance tested before 
shipment 

Complete package includes mike and 
coiled cord. 

Front panel power output selector 
switch : .1 1 1 and 1 watts. 

Can be used with power boosters. 

Mobile mounting bracket 



Also available without tone hut si encoder 



WRJTE OR CALL TODAY 

FOR COMPLETE SPECIFICATIONS 

AND PRICE DATA. 

DEALER INQUIRIES INVITED 

NEED A TONE BURST ENCODER? 
ASK FOR DATA ON THE MODEL 
TE-2, TE-5 AND TE-P 




Model RW-Bnd. SPECIFICATIONS 


Transmitter 




RF Power Output: 


0.1W ... ....Low 




LOW .Medium 




10W High 


Frequency Multiplication: 


12 (3X2X2) 


Oscillating Form: 


Crystal Controlled 


Modulation Form; 


Variable Reactance Phase 




Modulation 


Max, Frequency Shift? 


H-2QKHZ (1 KHz) 


S/N Response: 


More than 40 dB at 1 KHz 




70% Modulation 


Spurious Response: 


Jess than -60 dB 


Current Drain: 


0.5A for Low, 1.1A for Medium 


Receiver 


and 2,2A for High RF 


Receiving System: 
Intermediate Frequency: 


Double Super Heterodyne 


1st, 10.7 MHz 




2nd, 455 KHz 


1st Osc. Frequency Stability: 


0-002% 


Band Width: 


28 KHz at 6 dB down 




{Thru Mechanical Filter) 


Selectivity: 


60 KHz at 50 dB down 




(Thru Mechanical Filter) 


Sensitivity: 


6 dB (0.5UV) 


Squelch: 


-8 dB 


Audio Output: 


0.5W at 8 ohm impedance 


Current Drain: 


Q.22A max, including lamp 




0.15A when standing-by with 




Squelch 


Power Requirements 


13.5V DC ±10% 



'••••« 



ROSSmhite 

since 1932 company 

electronics 

50 W. DUNDEE RD, WHEELING, ILL. 60090 
312/537-0060 



APRIL 1972 



75 



VE7CAQ 


Trail 


VE7RPT 


Vancouver 


VE7BUZ 


Vancouver 


VE7ACS 


Vancouver 


VE7BEL 


Victoria 



VE4XK 



VE1PD 

VE1VHF 

VE1KI 



VOTGT 



VE1ARC 

VE1J0 

VE1XK 



VE3KBR 
VE3KCH 

VE3LCR 

VE3DRW 

VE3KER 

VE3LAC 
VE3KSR 

VE30SH 
VE3CRA 

VE3PBO 

VE3BER 

VE3STP 

VE3NRS 

VE3SAR 

VE3SSM 

VE3SRS 

VE3RPT 

VE3MOT 

VE3SIX 



VE2CRS 

VE2UV 

VE2PY 

VE2CSL 

VE2ASU 

VE2SP 

VE2TA 

VE2RM 

VE2XW 
VE2CAT 

V^ZCIA 

VE20M 

VE2VD 

VE2NY 

VE2MT 

VE2SS 

VE2CTM 

VE2AT 



34-94 
34-94 



14733 
146J22 



146.58 
147.54 



MANITOBA 



Winnepeg 



46-94 



NEW BRUNSWICK 



Crabhe Ml 
Moncton 
St John 



14730A 144,225A 



46-94 
46-94 



NEWFOUNDLAND 



St. John's 



46-94 



NOVA SCOTIA 



Halifax 
Sydney 
Truro 



46-94 
46-94 

46-94 



ONTARIO 



Belleville 
Chatham 

Grimsby 
Hamilton 



[on 
London 
Kitchener 

Oshawa 
Ottawa 

Peterbofouah 

Pt. Colborne FAX, 

Renfrew 

St. Catherines 

Sarnia 

SaultSte. Marie 

Sudbury 

Toronto 

Toronto 

Toronto 

Windsor 



14649 

14634 

146,46 

146.40 
443.30 

RTTY 
146.34 

146.22 



147.09 

14706 

147.06 

147,12 
44830 



46-94 
34-94 

16-76 



34-94 
37-97 

46-94 



449.40 146.70 
147.06 

147.24 



34-94 



34-94 
34-94 
46-94 



146.46 
146.58 
52.760 
146.40 



147.06 
147.18 
52.525 

147.06 



QUEBEC 



Chicoutimi 
Gran by 
Laval 
Matane 

Mont Buckfand 
Mont Jim Gray 
Mont Orford 
Mont Rigaud 

Mont St. Bruno 

Montreal 

Montreal 

Quebec 

Quebec 

Riviere-du-Loup 

Shawtandge 

Sherbrooke 

Thetford Mines 

Trois Rivieres 



46.68 

46.70 

146.52 
46.40 
444.00 

46.70 
46.10 

46.52 

46.46 
4634 



147.54 

147.60 

147.50 

147,18 

449,00 
147.60 

14730 

147.50 
147.06 
147.40 



46-94 

28-88 
46-94 

46-94 



18-64 

46-94 
46-94 
46-94 
46-94 



SASKATCHEWAN 



VE5SS 
VE5SK 



OE5XGL 

0E7XTI 

QE5XUL 



Q28JS 



D60WA 
OB8XA 

DBflZA 

OB0XB 

OL0JMA 

QLflSB 
DBflWF 

DLflBGA 
OB0WC 

DJ9CRA 

DB0WD 
DB0WT 
DBOZR 
OBflXR 

OBflWN 

DB0WE 



OK0RM 

DB0WG 

DB8WS 

DB8ZZ 

0B9XG 

DB8XH 

DB8WH 

DBflZH 

OB8YH 
DB8WV 

OB0YK 
DBflZF 



Regina 
Saskatoon 



146,46 



14733 



46-94 



FOREIGN 



AUSTRIA 



Altmuenster 
Innsbruck 
St. Johann 



144.15 
144,15 
144.15 



DENMARK 



Copenhagen T1 4S2.2 14535 
Hadersfey 14535 



GERMANY 



Aachen 

Altenwalde 

Audernach-Mayen 

Aschberg 

Bad Koenig 

Baederstrasse 

(Baltic Sea) 

Bamberg 

Bayreuth 

Bentheim Lingen 

Beflin 

Berlin 

Bocksberg 

(Han) 

Braunschweig 

Bremen 

Bremer haven 

Cham 

Coburg. 

Coxhafen 

Darmstadt 

Deggendorf 

Deisier 

Detmold 

Dortmund 

Dreilaendereck 

(Loerraeh) 

Duisburg 

Elm Mountain 

Essen 

Feldberg 

(Rhern Main) 

Frankfurt 

Frankfurt 

G lessen 

Goeppingen 

Goslar -Steinberg 

Grab 

Grading 

Hamburg 

Hannover 

Heidelberg 

Hersefeld 

Hoechenschwand 

(Black Forest) 

Hoechsten 

Hoher Meissner 

HombergKaiserslauten 

Kaisecstuhl 

(Freiburg) 

Kalrrtit 

Kassel 



144.20 
144.30 
144.25 

44.25 
44.175 
144.20 

44.20 
144.15 

44.20 

45.15 

44.15 

144.175 



44. 

44.25 

44.20 

44.15 

44.15 

44.15 

44.20 

44.20 

44.20 

144.25 
44,20 

144.20 

44.15 
44.80 
44.25 
44.15 

431.05 

44.15 
431.20 
44.175 
44.25 
144.20 
44.20 
44.15 
44,15 
44.25 
44.20 
144.25 



4435 

44.225 

44.20 

44,16 

4430 

44.15 



145.75 
145.75 

145.75 



145.85 

14535 



145.80 

145.70 

145.85 

14535 

145J75 

145.80 

14530 
14535 
145.80 
145.60 
145,75 
145.775 

145.89 

14535 
145.80 
145.75 
145.75 
145.85 
145.80 
14530 
14530 
14535 
14530 
145.80 

145.75 
145.90 
14535 
145.75 

43832 

14535 

438,80 

145.775 

14535 

14530 

14530 

145.75 

144.75 

14535 

14530 

14535 

14535 
145.825 
14530 
145.75 

145.70 

145.75 



76 



73 MAGAZINE 





feature after feature 

after feature 



Been denying yourself all that great fun so 
many other amateurs are having with their 
rock-solid, through the-repeater contacts? 

Delay no longer! Hasten to your SBE deal* 
er. Verify that the brilliant new SB-144 
has more channels-greater power output 
—starts your enjoyment now by including 
three sets of crystals on popular repeater 
frequencies and a high quality, SBE ex- 
clusive dynamic microphone without extra 
charge. Add a sizzling, double-conversion 
receiver and a combo lf S" and output 
meter with big lighted scale that also saves 
your battery by showing when the trans- 
ceiver is ON. 

Confirm the price then make the deal- 
Lose no time in securing this book-size 
beauty under your dash with the tiltable 
mounting bracket supplied. Then, power 
on! ENJOY! 



SB-144 



2 meter FM 

TRANSCEIVER 




10 WATTS 
OUTPUT 

ALL 

SOLID STATE 




12 

CHANNELS. 
SACK LIGHTED 
NUMBERS 





SUPPLIED 

WITH 

3 SETS OF 

CRYSTALS 





LARGE 

SCALE METER, 
COMBO, 

"S'VOUTPUT 





SUPPLIED 
WITH 
DYNAMIC 
MIC. 








ISBEI 




LINEAR 


SYSTEMS. INC. 




220 




Airport Blvd. 




Watsonvilta, CA 




95076 





APRIL 1972 



77 



Hi 




2 Meter 



6 Meter 

GENERAL ELECTRIC . . . RCA 





. MOTOROLA 



GENERAL ELECTRIC 



VOICE COMMANDER 1 1 1 



FULLY SOLID STATE FM 

Transmitter- Receiver 



132 to 174 MHz 

1 WATT OUTPUT 

1/2 MICRO- VOLT SENSITIVITY 

Size: 9.5" x 5.3" x 1,7" 

High Performance, completely self- 
contained two-way FM radio* Com- 
pact, lightweight, easily operated 
and hand-carried. Housed in high- 
impact 2-section case. All external 
hardware polished stainless steel. 

Includes rechargeable nickel cadmium 
battery pack and charger. . . , , 

$14800 

(Crystals & tuning, add $50) 

Lots of 5 less 10% . . . ea. $133.20 
Lots of 10 less 15% . . ea. $125.80 

Proper chargers available separately. $15. 

each. 




Nowi 15,000 2-Way FM 

Mobile Units In Stock! SEND FOR NEW 
1972 CATALOG 



GREGORY ELECTRONICS CORP 



The FM Used Equipment People 
243 Route 46, Saddle Brook, N J. 07662 

Phone (201) 4899000 



Dept. 73 



78 



73 MAGAZINE 



/ 



± 



IMPROVED. 

5w AUDIO OUT ppd u 

3CERAMIC I.F 
FILTER&MORE 



J f,EC0 H/IM 



* __ • 



lj u 



LOEC 



RECEIVER PCBD$68J 

XMITTER PC BD $ 79.10 

ROOF SIDE ANT. 



NEW SUPER FIBERGLASS 

TELESCOPIC ANTENNA 

3 Sections or 8 Sections 
STAINLESS STEEL ELEMENTS 

VSWR. 1.1:1 

ounting brackets Cable incl. 



Teiecomm Electronics 
PO.Box461.Cupertino,Ca.95014 






APRIL 1972 



79 



FREQUENCY STANDARD 




Only 
$32.50 

(less batteriesl 
POSTPAID USA 



Precision crystal 



• Fully guaranteed 



Markers at TOO, 50, 25, 1 or 5 kHz se- 
lected by front panel switch. 
Zero adjust sets to WWV. Exclusive circuit 
suppresses unwanted markers. 
Compact rugged design. Attractive t com- 
pletely self contained. 
Send for free brochure* 



BOX 455, ESCONDIDO, CA 92025 



DOUBLE YOUR 
RANGE! 

Four times the POWER equals 
twice the range - 

2m FM Amplifier 

4/12 W IN -20/50 W OUT 

Matches 

Drake ML SR826M 

Tempo VMF IC2F 

Regency HR2 Swan 1210 

Simpson A SB 144 

Ross & White Etc. 

Sonar 3601 

All automatic TR switching. 7x5x3. 
Model 1050. Order direct $99.95 

VHF Specialists Box 167 

VIENNA, VIRGINIA 22180 



TEST EQUIPMENT 

INDUSTRIALS Ml LITARY SURPLUS 

SEND FOR FREE FLY SHEETS ON 

ALL CURRENT EQUIPMENT 

HARD TO RESIST PRICES 

SID GLASS & CO. 

BOX 788 
BEVERLY HILLS, CALIF. 90213 



m m 


Koblenz 


144.20 


145.80 


- - 


Koeln-Beigheim 


144.25 


145.85 


DB0WK 


Koustanz 


144J5 


14575 


_ _ 


Knuell 


144.25 


145.85 


DBBWL 


Lahr 


144.15 


145.75 


— — 


Leer/Ostfriesiand 


144.20 


145.80 


DJ3JWA 


Lindau-Bertz 


144.15 


145.85 


-- 


Lindau-Northeim 
(Hannover) 


144.20 


145,80 


DLOBLB 


Ludwigsburg 


144.85 


H5.30 


DBflYY 


Ludwigsburg 


144.30 


145.70 


D80ZL 


Luechow/Eibe 


144.20 


145.80 


OB0XS 


Merzig/Saar 


144*25 


145.85 


DB8ZM 


Munich 


144.15 


145.75 


DB0WM 


Muenster Attest f. 


144.25 


145.85 


DB0ZN 


Nenersberrj 


144.15 


145.75 


D10WFA 


IMurnberg 


144.15 


145.85 


DB0ZB* 


Ochsenkopf 


144.25 


145.85 


DB9WN 


Ochsenwarig 


144225 


145.825 


DB8Z0 


Osnabruck 


144,15 


145.75 


DL0ZR 


Schwerte 


145.15 


145.90 


DB0WS 


Siegen 


144.20 


145.80 


DB0WR 


Stuttgart 


144,15 


145.75 


OB0WX 


Triberg 


144.20 


145.80 


DB0ZW 


Weiden 


144.20 


145.80 


DB0WB 


Winterberg 


144.15 


145.75 


DB0WZ 


Wurzburg 


144.25 


145J5 


DB0ZU 


Zugspitze 


144.275 


145.725 



NEW ZEALAND 



New Zealand has been working on a 2 meter band plan for the 
country, with provision for all modes of operation. There are FM 
simplex channels every 50 kHz from 145,8 to 146.2 MHz, with 145.85 t 
146.0 and 146.15 MHz, as the prime channels. 146.0 MHz to be first. 
On the FM repeater side they have allocated four channels on 700 kHz 
spacing. A pity, as it does not make them compatible to Australia. 
Inputs on 146.3, .35, .4 and .45 with the outputs on 145.6, .65, .7 and 
75. The three-channel AM repeater systems have inputs on 144.6, .65 
and .7 with the outputs on 145.725, .775 and .825. 144.8 MHz is set 
aside as an RTTY net frequency. The beacons are on the "hundred" 
equal to the call area, e.g. ZL1 on 145.1, ZL2 on 145.2, ZL3 on 145.3, 
and ZL4 on 145.4 MHz. The segment 144.0 to 144.1 MHz is set aside 
as OX and experimental working. 144.1 to 144.5 MHz is a general 
working segment. 



SWEDEN 



SK0DZ 



Stockholm T2.172 144.90 
RommeteasenT2.172 144.90 



145.80 
145.80 



SWITZERLAND 



Appenzell T1.595 


431,20 


438.80 


FribouFf T1.29 


431.05 


438.92 


Luzern T1.16 


431J2Q 


438 80 


Luzern T 1.595 


431.05 


438.92 


Solothurn T1.18 


431.20 


438,80 


Zurich T1.16 


431.05 


438.92 



80 



73 MAGAZINE 



HIGH GAIN • LOW NOISE 



40 dB GAIN 2.5-3.0 N.F 
1 150 Mf 




35 dB power gain, 2-5—3,0 dB 
N.F, at 150 MHz, 2 stage, R.F. 
protected, dual-gate MOSFETS. 
Manual gain control and provi- 
sion for AGC, 4-3/8" X 1-7/8" 
X 1-3/8" aluminum case with 
BNC receptacles and power 
switch. Available factory tuned 
to the frequency of your choice 
from 5 MHz to 350 MHz with 
approximately 3% bandwidth. 
Up to 10% B.W, available on 
special order* 
Model 201 price: 

5-200 MHz ..„..-.. 421,95, 

201—350 MHz. . . . ,$24.95 . 



Iiup 3 to 5 dB MAX. N.F. 
ur,r 20dB Ml N.POWER GAIN 




The Model 202 uses 2 of T.I.'s 
super low noise J-FETS in our 
special circuit board design 
which gives a minimum of 20 
dB power gain at 450 MHz. 
Stability is such that you can 
have mismatched loads without 
it oscillating and you can retune 
(using the capped openings in 
the case) over a 15—20 MHz 
range simply by peaking for 
maximum signal. Available 
tuned to the frequency of your 
choice between 300—475 MHz. 
4-3/8" X 1-7/8" X 1-3/8" alu- 
minum case with BNC recep- 
tacles and power switch. 
Model 202 price: . . . . . .$31.95. 



VHF FM RECEIVER 
11 CHANNELS • 135-250 MHz 




• 11 crystal -controlled chan- 
nels. * Available in your choice 
of frequencies from 135—250 
MHz in any one segment from 
1—4 MHz wide. • I. F. band- 
width (channel selectivity) avail- 
able in your choice of +/ — 7.5 
kHz or +/— 15 kHz. • 8-pole 
quartz filter and a 4-pole cera- 
mic filter gives more than 80 dB 
rejection at 2X channel band- 
width. • Frequency trimmers 
for each crystal, • .2 to .3 
/Uvolt for 20 dB quiet- 
ing. • Dual -gate MOSFETS and 
integrated circuits. • Self-con- 
tained speaker and external 
speaker jack. • Mobile mount 
and tilt stand • Anodized alum. 

Case, 6" X 7" X 1 3/8". 
Model FMR-2 50-11 price: 

135—180 MHZ. $109.95 

181—250 MHz $119.95 

Price includes one .001% crys- 
tal. Additional crystals $6.95 ea, 





2 RF stages with transient pro- 
tected dual-gate MOSFETS give 
this converter the high gain and 
low noise you need for receiving 
very weak signals. The mixer 
stage is also a dual-gate MOS- 
FET as it greatly reduces spur- 
ious mixing products — some by 
as much as 100 dB over that 
obtained with bipolar mixers. A 
bipolar oscillator using 3rd or 
5th overtone plug-in crystals is 
followed by a harmonic band- 
pass filter, and where necessary 
an additional amplifier is used 
to assure the correct amount of 
drive to the mixer. Available in 
your choice of input frequencies 
from 5 — 350 MHz and with any 
output you choose within this 
range. The usable bandwidth is 
approx. 3% of the input fre- 
quency with a maximum of 4 
MHz. Wider band widths are 
available on special order. Al- 
though any frequency combina- 
tion is possible (including con- 
verting up) best results are ob- 
tained if you choose an output 
frequency not more than 1 /3 
nor less than 1/20 of the input 
frequency. Enclosed in a 4-3/8" 
X 3" X 1-1/4" aluminum case 
with BNC receptacles, power 
and antenna transfer switch. 

Model 407 price: 

5—200 MHz ......... $42.95. 

201—350 MHz . $44.95 



Prices include .005% crystal. 
Additional crystals $5.95 



ea 



WVEATHERPROOFED AND 
D.C.POWERED THROUGH 
ANTENNA CABLE 




Models 101 and 102 only are 
available enclosed in a die-cast 
weatherproof case for mounting 
at the antenna in series with the 
lead-in cable and includes a fil- 
ter for sending 12 VDC through 
the cable. Can be used only for 
receiving unless you put a TR 
switch at the antenna. Available 
with your choice of VHF, BNC 
or type **N" receptacles. Espe- 
cially useful for eliminating an- 
tenna line loss arid thereby im- 
proving signal-to^ioise ratio of 
weak signals such as those from 
weather satellites at 137 MHz. 
Price: Add $10.00 to pre-amps, 




LESS THAN 2 dB N.F. GAIN 
20 dB @ 150 MHz. SIZE: 2K" 
X5/8X 1" 



VANGUARD 



Features a super low noise J- 
FET rated by T.I. as typically 
1.2 dB N.F, @ 150 MHz (transis- 
tor data curves supplied with 
unit) and guaranteed by our lab 
to give under 2 dB actual N.F. 
in our circuit. Transistor is 
mounted in a socket with gold 
plated contacts. 4 precision 
trimmers make possible tuning 
for optimum desired results over 
a wide range of conditions. We 
supply it tuned for minimum 
noise figure across 50 ohms in- 
put and output resistance. Fully 
shielded in aluminum case with 
feed-thru solder terminals. Sup- 
plied with mounting kit for in- 
stalling inside or outside your 
receiver. Tuned to the frequen- 
cy of your choice from 135 
MHz to 250 MHz with approxi- 
mately 2—4 MHz bandwidth. 
Model 102 price: $19.95. 



UHF 



20dBMIN. GAIN 
3 to 5 dB MAX. N.F 




This model is similar in appear- 
ance to our Model 407 but uses 
2 low noise J-FETS in our spe- 
cially designed RF stage which 
is tuned with high-Q miniature 
trimmers. The mixer is a special 
dual-gate MOSFET made by 
RCA to meet our requirements. 
The oscillator uses 5th overtone 
crystals to reduce spurious re- 
sponses and make possible fewer 
multipliers in the oscillator 
chain which uses 1200 MHz 
bipolar s for maximum effi- 
ciency. Available with your 
choice of input frequencies 
from 300—475 MHz and output 
frequencies from 14 — 220 MHz. 
Usable bandwidth is about 1% 
of the input frequency but can 
be easily retuned to cover more. 
This model is now in use in 
many sophisticated applications 
such as a component of a com- 
munications link for rocket 
launchings. 

Model 408 price: $51.95 

.005% crystal included. 



HOW TO ORDER: 

State model, input and output 
frequencies and bandwidth 
where applicable. Remit in full* 
including sales tax if you reside 
in N.Y. State, direct to Van- 
guard Labs. Prices include post- 
age by regular parcel post. For 
air mail or special delivery in- 
clude extra amount; excess will 
be refunded. 




196-23 JAMAICA AVE.. HOLDS. N.Y. 1 1423 



ADDII 1Q79 



81 



■I 





for every use . . . 
for every pocketbook! 

NEW! HAN DY-T ALKY 
STANDARD 



-146 



5 Channels 



94/.94 and .34/. 94 supplied 
— 1.5 W transmitter 



.3 uV receiver — 

Compact — 8"h x 3" w x Vh d 

Full line of optional accessories includes external 
speaker- mike — desktop charger — "stubby" an- 
tenna — and more! 

Available NOW! — Only $279.00 



ALL PURPOSE 



STANDARD 826M 

12 channels (4 with crystals) 

10 Watt output 

All solid state 

Hot MOSFET receiver 

Only $339.95 



l # 



i 



TEMPO SOLID-STATE POWER AMPS 




MODEL 


DRIVE POWER 


OUTPUT POWER 


PRICE 


1002 3 


5-25 watts 


100-135 watts 


$220 


1 002-3 B 


1 2.5 watts 


120-130 watts 


$235 


802 


5~t2 watts 


70-90 watts 


$165 


802B 


1 -2.5 watts 


SO 90 watts 


$180 


502 


5-1 5 watts 


35-55 watts 


$ 99 


502B 


1-2.5 watts 


45-50 watts 


$125 


242-A2 


1-2.5 watts 


25-30 watts 


$ 85 



And many more from SBE/Clegg /Gladding /Kenwooo '/Tempo /Antenna Specialists /Larsen 

All U.S. Made 
And many more from Dycomm/Kcnwood /Tempo/ Antenna Specialists 

Make ERICKSON your headquarters for all your FM needs . 
SEHD QSL FOR COMPLETE SPECIFICATIONS 




r w 



ERICKSON COMMUNICATIONS 

4653 N. Ravenswood Ave., Chicago, III. 60640 (312) 334-3200 



82 



73 MAGAZINE 



The 




Meter FM Rig 






The Experts Praise 



£L4hblh£ 25 




6 CHANNELS/2 METER/TRANSCEIVER/25 WATTS 

Power is the keyword when discussing Gladding 25™, 
the two meter transceiver the experts recommend. 

Gladding 25 is so similar to our marine gear (we're the 
leader in AM and FM marine communications) we are able 
to take advantage of the tremendous buying power and pro- 
duction efficiencies our huge volume gives us. The result is 
remarkably low priced. A Gladding 25™ has the power, price 
and the features amateurs want most, with unmatched quality. 



• 25 Watts output • 0.3 micro volt uv sensitivity for 12 db 
SINAD • Dynamic microphone for unmatched audio • Six 
separately switchable transmit and receive channels • Crystal 
supplied for 149.94 simplex and repeater capability on 
146.34/146.76 and 147.34/146.94 mHz • 12 volt mobile unit 
has matching accessary AC power supply • Vacuum tube 
driver and final for reliability and economy • 8 pole crystal 
lattice filter • Solid state receiver • Transistor sockets • Glass 
epoxy printed circuit boards • Quick disconnect power plugs 

• Mobile mounting brackets • One watt output capability 
for short range communications, 

Write for complete information. 



PEARCE-SIMPSON 

DIVISION OF £L4bbir\£ CORPORATON 

P.O. Box 800, Biscayne Annex, Miami, Florida 33152 



5249 

for mobile unit 

$29995 

with accessory AC 
power supply 



95 





SUB -AUDIBLE TONE ENCODER and DECODER KITS 

• Compatible with all sub-audible tone systems such as Private Line, Channel 
Guard, Quiet Channel, etc. 

• Glass epoxy PCB's and silicon transistors used throughout 

• Any type reeds may be used: Motorola, G.E,, RCA, S.D.L*, Bramco, etc. 
except special dual coil types 

• All are powered by 12 vdc 

• Use on any tone frequency 67 Hz to 250 Hz 





$8.95 - Kit 

$13.95 - Wired- 

Tested 



$9.95 - Kit 

$14,95 - Wired- 

Tested 



ENCODER 

Small size 1.5 x 4 x 
75" 

All parts included ex- 
cept reed and reed 
socket 

Output 4v RMS sine- 
wave, low distortion 

WIRE-IN TYPE 
DECODER 

► Same small size as en- 
coder L5 x 4 x .75" 

> All parts included ex- 
cept reed and reed 
socket 

> Output relay in- 
cluded, low profile 
sealed type. 

► Driven directly off dis- 
criminator of any FM 
receiver 




$14.95 - Wired-Tested 



MINIATURE ENCODER 

Miniature in size 2.5x .75x1.5" high 

Any miniature dual coil contactless 

reed may be used (Motorola 

TLN6824A, TLN6709B - Bramco 

RF-20) 

Complete less reed (Available in 33 

frequencies for $17.50 ea.) 

Output 3v RMS sinewave, low dis- 
tortion 



All material shipped postpaid (Calif, residents add 5% sales tax) 
Send check or money order to: 

Communications Specialists 

P.O. BOX 153 • BREA, CALIFORNIA • 92621 



84 



73 MAGAZINE 







arm 

COMMUNICATIONS 





MOTOROLA m44BBT-3000 
450 MHz MOBILE RADIO UNIT 
10" HOUSING 

TRANSISTOR POWER SUPPLY 
LESS ACCESSORIES $59.00 



ACCESSORIES AVAILABLE 



MOBILE PURCHASE 



WRITE FOR FREE CA TALOG 



Mann Guarantee 

Money refunded without question if equ*p 
ment is returned within seven days from 
shipment, undamaged, freight prepaid. 



Conditions of Sale 

Unless otherwise specified, equipment is 
used, and is sold asrs. All items shipped 
FOB Tarzana, California. Crystals, ovens, 
antennas not included unless specifically 
stated in catatog. All equipment is sold on 
a first-come, first-served basts* 



ann communications 



18669 Ventura Blvd. 

Box 138 Tarzana, CA 91356 

(213) 342-8297 



2837 North 24th Street 
Phoenix, Ariz 85008 
(602) 955-4570 



APRIL 1972 



85 






ELECTRON 1 C 



SYMBOLS 



ANTENNA 




NORMALLY USED <N BLOC* DIAGRAMS, OUT MAY BE USED IN ANY 
SCHEMATIC WHERE ANTENNA tS CONNECTED DIRECTLY TO CIRCUIT 
WITHOUT BENEFIT OF RF CONNECTOR 



SINGLE 
_£LL_ 



BATTERY 



1- 

MORE THAN 

ore ceil 



DO NOT FORGET TO INDICATE VOLTAGE 
ANO POLARITY 



GROUND CONNECTIONS 



X X 



CHASSIS EARTH 



CHASSf5 GROUND SYMBOL IS NORMALLY THE ONLY TYPE 
USED IN SCHEMATICS 

EACH GROUNDED CIRCUIT COMPONENT WILL BE SHOWN 
CONNECTED TO AN WDMDUAL CHASES GROUND, UNLESS 
A COMMON GROUND BUS «S ESSENTIAL TO PROPER 
CIRCUIT OPERATION 




HEADSET 



NORMALLY USED IN ©LOCK DIAGRAMS, BUT MAY BE USED IN ANY 
SCHEMATIC WHERE CONNECTED OlRECTLY INTO CIRCUIT WITHOUT 
PHONE PLUG 

INDICATE IMPEDANCE IF VALUE IS CRITICAL 



CAPACITORS 



BASIC 



* T 

ELECTROLYTIC 





# 



variable 



TV TV 






SPLIT*STATDR GANGED 



DIFFERENTIAL 





VACUUM 



VAC. VAR. 



NOTE THAT CURVED PORTION OF 
SYMBOL ALWAYS DESIGNATES 
OUTSIDE FOIL OF FWED CAPACI- 
TORS (EXCEPT ELECT ROLYTICS. 
WHERE *T INDICATES THE NEG- 
ATIVE TERMINAL) 

THE CURVED PORTION fN THE 
CASE OF A VARIABLE WILL 
INDICATE THE MOVABLE PART 

*INOCATE POLARITY, ANO 
VALUE IN yW 

WHEN OTHER THAN ELECTRO - 
LYTIC .VALUES ARE ASSUMED TO 
BE pF WHEN \ OR GREATER. AND 
jnF WHEN LESS THAN 1 



INDUCTORS 




BASIC TAPPED AD J, TAP 




ADX SLUG FILTER 
# CHOKE 



RF 

CHOKE 



INCLUDE ALL NECESSARY DATA INCLUDING 
ANY OP FOLLOWING INFORMATION WHICH 
IS APPLICABLE 

WIRE SI2E & TYPE 
COIL OR FORM Q + th OR 1,0, 
NUMBER OF TURNS AND/OR LENGTH 
MANUFACTURERS RftRT NUMBER 
TAP POSITION ABOVE COLD END 

* FERRITE CORE WILL BE ASSUMED 
UNLESS BRASS IS SPECIFIED- INDICATE 
TYPE OF FERRITE JF CRITICAL 



CONDUCTORS 



BASiC 



4 



CONNECTED 



CROSSED 



CONNECTORS 





MALE FEMALE 

AC LINE 

I k i 

MALE FEMALE BASIC 
TERMINALS 






FiKEO MOVABLE 

MULTIPLE * 



O- 



I 



V] 



T^~ 



PHONE PLUG PHONE JACK COAXIAL * 



SHOULD NONE OF THE 
SYMBOLS DESCRIBED HERE 
SEEM TO MATCH YOUR 
SITUATION, DESCRIBE THE 
CONNECTOR AND/OR LIST 
THE MANUFACTURER'S 
PART NUMBER 

♦ FOR ANY COAXIAL-TYPE 
CONNECTOR, SUCH AS RF. 
MICROPHONE, PHONO, ETC. 

■3f NUMBER THE BLOCKS TO 
CORRESPOND TO TERMINAL 
MARKINGS. WHEN APPROPRI- 
ATE 



CRYSTAL 



ALWAYS INDICATE CRYSTAL FREQUENCY UN kHi.MHi .ETC J 



ELECTRON TUBES 







DIODE 



TRIOOE 



TETRODE 



PENTODE 







PENTAGRID 



VOLTAGE 
REGULATOR 



EXAMPLE OF MULTIPLE 
SECTION TUBE 




PLATE 



CATHODE RAY 



GRID 

CATHODE i 1 

♦ HEATER /\ 
{FILAMENT} 



DEFLECTION PLATE. 



GAS FILLED 



? 



COlD CATHODE 



ALWAYS LABEL 
ELEMENTS WITH 
TUBE PIN NUM- 
BERS 

REFER TO TUBE 
MANUAL FOR 
DATA ON INDIVI- 
DUAL TUBE TYPES 

£- FILAMENTS OR 
HEATERS (WITH 
THE EXCEPTION 
OF DIRECTLY- 
HEATED CATH- 
ODES) SHOULD BE 
SHOWN EXTERNAL 
TO TUBE CIRCLE, 
AND PREFERABLY 
IN THE POWER 
SUPPLY 







FUSt 




INDICATE CURRENT .VOLTAGE RATINGS, AND SLO'BLO, ETC., 
AS APPROPRIATE 


—11 


D- 





KEYS 





STANDARD 



AUTOMATIC 



* BE SURE TO DESIGNATE 
"DIT" & "DAH" CONTACTS 



LAMPS 



INCANDESCE 



NT ^-^NEON 



INDICATE MANUFACTURER'S PART NUMBER 
AND/OR VOLTAGE S CURRENT RATING 



LOUDSPEAKER 




INDICATE VOCE COIL fMPE DANCE & POWER RATING .ETC.. WHEN 
CRITICAL 


W 



METERS 




♦ INDICATE TYPE OF METER HERE IjjA.fT^V.ETCJ 
•A- INDICATE SCALE RANGE HERE t 0-1 .0-50. ETC. ) 
DON'T FORGET TO INDICATE PROPER POLARITY 




MICROPHONE 



NORMALLY USED IN BLOCK DIAGRAMS BUT MAY BE USED 
IN SCHEMATIC WHEN WIRED DIRECTLY INTO CIRCUIT 
WITHOUT CONNECTOR 

INDICATE TYPE (CARBON, XTAL.ETC .) 



MOTOR 




LABEL AS MOTOR, FAN MOTOR, ETC, 

INDICATE OPERATING VOLTAGE i CURRENT AND'OR 

MANUFACTURER'S PART NUMBER 



RELAYS 



( 



) 




RELAY COIL 



SPST DPST SPOT 

CONTACT CONFIGURATIONS 



SPECIFY COIL VOLTAGE, 

RESISTANCE f ETC. t AND/OR 
MANUFACTURER'S PART 
NUMBER 

CONTACT CONFIGURATIONS 
SHOWN ARE BASIC AND 
MAY BE EXPANDED 



RESISTORS 



1 |-H 

FJXEO TAPPED ADJUSTABLE TEMRCQMP. 



INDICATE VALUE , IN QHM5t.rU 
KlLQHMStfcLOR MEGOHMS (M). 
AND/OR MANUFACTURER'S 
PART NUMBER 
l/ZW *0% IS ASSUMED 
UNLESS OTHERWISE NOTED 



O 



EMICONDUCTOR DIODES 



* * 



BASIC 



ZENER 



TUNNEL CONTROLLED 




SYMETRICAU 
ZENER 



P-i-N 



INDICATE MANUFAC- 
TURER'S PART NOV 
RER AND/OR AP- 
PROPRIATE RATNGS 

REFER TO MANUALS 
FOR SYMBOLS NOT 
SHOWN 

S INDICATES SILICON 
G " GERMANIUM 



86 



73 MAGAZINE 



ELECTRON I C 



SYMBOL S 



[ 



i 

i 
i 
i 

i 
i 
t 
i 
i 

bask: 



S D ST 



SHIELDING 



i 
i 

i 
i 



r~f~7 /T7 



1 I 

I I 

K I 

SHIELDED 
ASSEMBLY 



H-* , 

f t 

i r 



j; 



SHCiDED 

MUlHPLE 
*'*£S 



COAX 



f 



"A NAJC 



SHiEtDS ARE AS- 
SUMED TO BE 
GROUNDED UNLESS 
OTHERWISE NOTED 

INDICATE IF SHIELD 
ON CONDUCTOR IS 
TO BE GROUNDED 
ONE END ONLY, & 
SPECIFY WHICH 
END 



J 



SWITCHES 



a^ o o^ 






SPOT 






NX. 



NO 



O S^ST 

ROTARY p USM BUTTON 

T \- CONTACT 



O 
$PDT 
CENTER- OFF 



O 
DPDT 



ONLY BASIC CONFIGURATIONS 
ARE SHOWN. COMBINE OR EX- 
PAND AS NECESSARY TO SUIT 

SELF-HQLDING switch 

operation is assumed unless 
spring-return is specif ieo 

NON-SHORTING TYPE IS ASSUM- 
ED UNLESS SHORTtNG TYPE IS 
SPECIFIED 

'SWITCH SECTIONS WHICH ARE 
SIMULTANEOUSLY OPERATED OR 
GANGCO SHOULD BE JOINED 
WITH A DOTTED LINE 



TRANSFORMERS 






BASIC 




IRON- LQW-Z VARlAC 

CORE SECONDARY 



OR 



i.F. transformer 




SHOW i4J LOOPS EACH WINDING 
EXCEPT re J LOOPS ON HIGH- 
VOLTAGE SECONDARIES AND tZ3 
ON FILAMENT WINDINGS AND 
NON- RESONANT LOW-Z RF 
COUPLING LINKS 

TRANSFORMER DESCRIPTION 
SHOULD INCLUDE MANUFAC- 
TURERS PART NUMBER AND 
RATINGS. OR CONSTRUCTION 
DATA 



RANSISTORS 





PNP 



NPN 



F IELD-EFFEC T 

P-TYPE N-tvde 

IGFETS fMOSFETS* 



* 



SPEC'Ff MANUFACTURER'S 
PART NUMBER OR RATINGS 

REFER TO TRANSISTOR 

MANUALS FOR TYPES NOT 
SHOWN HERE. 



TYPICAL DK> C ET 




PN NP 

UNI- JUNCTION 




P-TYPE 



n- ryef 




ELECT 



RONIC ABBREV 

IAS USED ON DRAWINGS AND SCHEMATICS} 



I A T I N S 



NOMENCLATURE 



ALTERNATING CURRENT 
AMPERE 

AMPLIFIER 

AMPLITUDE MODULATION 

ANTENNA 

AUOK) FREQUENCY 

AUTOMATIC FREQUENCY CONTROL 

AUTOMATIC GAIN CONTROL 
AUTOMATIC VOLUME CONTROL 

SATTERY 

BEAT PRE QUE NOT OSCILLATOR 

BROADCAST 

CAPACITANCE, CAPACITOR 

NTIMUOUS WAVE 
CRYSTAL 
CURRENT 

^ECiBCL 

DIODE, SEMICONDUCTOR (ALL TYPES I 

DiRECT CURRENT 

DOUBLE COTTON COVERED 

DOUBLE POLE DOUBLE THROW 

DOUBLE P0lE SINGLE THROW 

DOUBLE SILK COVERED 

ELECTRON TUBE TAll TyPESl 
ENAMEL COVERED 

^LAMENT 

FREQUENCY 

FREQUENCY MODULATE '. 

fuse 

GROUND 

HE NR 1 ! 

HERTZ (CYCLES PER SECOND I 

IMPEDANCE 
(NOUCTANCE, INDUCTOR 

NSOC D'AMEYER 
INTERMEDIATE FREQUENCY 

JACK 



(KILOCYCLES PER SECOND > 



KN_OH£RTZ 

_QHM 

ki^ovc • 

K1LC*AT T 



LAMP 

LO '-©SPEAKER 

MEGAHERTZ t MEGACYCLES- PER 5CCON0I 
MEGOHM 

METER 

MICROAMPERE 

MCROFARAO 

MICROHENRY 



ABBREVIATION (S) 



AC 

A 

AMP 

ANT 

AF 

AFC 
AGC 

AVC 

e 

BO 

C 

CW 

X, KTAl 

J 

dB 

D 

DC 

OXX. 

DPDT 

DPST 

DLSX, 

V 
ENAM 

FIL 

FREQ* t 
v 

t 

GND 

H 
Hj 



L 

.3. 
LF 



IV 



SP«P 
MHj 



|^A 

mH 



^™ 



NOMENCLATURE 



MICROPHONE 

MICROVOLT 

MICROWATT 

MiLLlAMPERE 
MILLIHENRY 

MILLIVOLT 

MILLIWATT 

NEGATIVE [POLARITY) 
NORMALLY CLOSED 
NORMALLY OPEN 

OHM 

oscillator 
outside diameter 

picofarad 
plug 

POSITIVE \ POLARITY) 

POWER AMPLER 
PRIMARY 

PUSHBUTTON 

RADIO FREQUENCE 

RADIO FREQUENCY CHOKE 

RECEIVE 

RECEIVER 

PEL AT 

RESISTANCE, RESISTCR ULL TYPES I 
ROOT MEAN SQUARE 

SECONDARY 

SHORTWAVE 

JINGLE CCTTON COVERED 

SINGLE ROLE DOUBLE THROW 

SINGLE ROLE SINGLE THROW 

SINGLE SILK COVERED 

SWITCH 

TIME 

TRANSFORMER 

TRANSISTOR [ALL TYPES) 

TRANSMIT 

TRANSMITTER 

ultra high frequency 

vacuum tube voltmeter 
very high frequency 
vQlt ohm meter 
VOLT, volts 

VOLTAGE 

WATT 
WAVELENGTH 



■ ^SREAATIQN(S) 

MiC 

fV 

mA 

mV 
mw 

-, NEG 

NC 

NO 

A 

DSC 
O.D. 

p 

* POS 

PA 

PRi 

PB 

RF 
RFC 

REC 
RCVR 

* 
R 
RMS 

SEC 
SW 
S,C.C. 
SPD T 
SP " 

s.s.c 
s 

I 

XFMR,T 

Q 

*M«T 

XMTR 

UHF 

VTVM 

VHF 

VOW 

V 

E 

w 



APRIL 1972 



87 








WATTS 




THE 



HAND 



Channels 




Unimetrics 
MINIVOX- iy 

Regularly $429 95 



unimcTRics, int 

23 WEST MALL. PLAINVIEW; N. Y. 11803 



Close Out Special 
for Amateurs 

$229 95 

w/one set of crystals 

13.8V Battery Pack 
.5 ytV Sensitivity 
30 kHz channel spacing 

Accessories — 

Tone deck 

Resonant reed 

xtra sets of crystals . . 

Nicad Battery Pack . . 

Nicad Battery Charger 

PTT Speaker Mike . . 

Leather carrying case 

Spring type antenna . 
> Rod type antenna . . . 

Telescoping antenna . 



$24.50 
$15.00 
$15.00 
$24.35 
$32.50 
$16.50 
. $7.95 
. $7.50 
. $7.50 
. . $7.50 



88 



73 MAGAZINE 



with 




VHF mobiles 



you can be sure 



of OPTIMUM 



Typical 

BBL 
Models 



1.5 £ 



6 & 2 METER MOBILE 







4 



HF-62 HF-2 



Heavy duty, precision fit, four 
section telescopic antenna tunable 
separately for combined six and 
two meter operation. Extends to 
44*. Collapses to 22*. 

Model HF-2: Antenna supplied 
with J4*-24 base to fit any stand- 
ard antenna mount, $9,50 

Model HF-62: Supplied with 
automotive eight ball base for 
tender or cowl mounting, Includes 
GO' RG-58-U and connectors. 
$11.95 



Tops in 
Rooftops 

140-500 MHl— 
UHF/VHF Antenna 

Low profile, roof top 

with factory attached 
cable— installs from 

outside without dis- 
turbing car header, 
177 PH stainless 
radiating element - 
field trimmed for 
frequencies between 
140 and 500 MHz. ^ 
Complete with 15' 
RG-58-U coaxial cable. 

Model UHT-l 

|7.75 

Trunk Lip 
Mount 

140 500 MHz UHF/VHF 

Easy to install on side or 
rear of trunk lip. No holes 
to drill or coax to trim. 
17-7 PH stainless steel 
radiating element. Chart 
included for 140-500 MHz 
coverage. Complete with 
17' RG-5S-U and PL-259 

Model THF 
$12.95 





your signal 

MILES 



NEW! 




2 METER 
POWER GAIN 

143-149 MHz 
3.4 db gain — % wavelength 
Power rating: 200 watts FM 

Get the experience of solid communica- 
tions, extended range and full quieting 
with the Hustler BBL models. Optimized 
gain performance with lowest SWR and 
the superior mechanical construction will 
give you the extra advantage. Both 
models supplied operational, ready for 
easy installation. 

Model BBL-144: Mounts on any flat surface in 
V hole— easy installation on roof, (without 
pulling cars' header), deck or fender— complete 
with adjustable, taper ground stainless steel 
radiator, stainless steel spring. Overall height 
approximately 47", 17' RG-58-U coax with 
PL 259 connector. $27.70 

Model BBIT-144: Same as BBL-144 with 
Hustler trunk lip mount for no holes to drill 
installation on side or rear of trunk lip. Heavy 
duty mount assures "stay-put" operation, posi- 
live RF ground for lowest SWR and completely 
hidden cable. $34.70 



Exclusive Hustler 
"break cable" 
assembly for 
simplest 
installation 
of all! 




World leader in Antenna Mounts — send for Catalog today! 

NEW-TRONICS CORP. *£££*+. 

15800 COMMERCE PARK DRIVE "" *** - «*-*»T# 

BROOK PARK, OHIO 44142 



Recognize the BEST! 





BBLT-H4 



BBL-144 



World Wide Export Robum Agencies, Inc., 349 W. Mth St.. New York, N.Y. 10014, Cable Address: Roburnage - New York 



APRIL 1972 



89 








V 



AMATEUR 

GENERAL 

CLASS 

LICENSE 

STUDY 

GUIDE 



RADIO 





AMATEUR 

RADIO 

ADVANCED 

CLASS | 

LICENSE 

STUDYI 

GUIDE J 

I 



AMATEUR 
RADIO 

EXTRA 
CLASS 

LICENSE 

STUDY 

GUIDE 





\ 




A The Novice Class Li- 
cense Study Guide has not 
yet been published in 73 or 
in any other magazine. 
This book contains all the 
basic technical information 
need 10 pass the Novice 
License with flying col- 
ors. . .and is invaluable as a 
basic text for understand- 
ing the General Class Study 
Guide. Profusely illustrated 
and so clearly written that 
just reading it is enough to 
permit most applicants to 
pass their exam, $3.95 
value. 



B The 73 General Class 
Study Guide has helped 
thousands to easily pass 
their General License the 
first time through. At $9 a 
whack, isn't it foolish not 
to hedge your bet with this 
comprehensive and simple 
book? No other study 
guide is as complete or as 
easy to read. None. A 
$4.95 value. 



C The Advanced Class 
Study Guide has proven to 
be the only complete text 
for preparing to pass the 
Advanced Class license 
exam. Never before has 
radio theory been made so 
simple. After just reading 
this book it fs almost im- 
possible to fail that exam. 
And remember that in ad- 
dition to the trouble of 
going to the FCC to take 
that exam, there is a little 
matter of $9 you have to 
ante up. Why take a chance 
on failing? $5.95 value. 



D The Extra Class License 
Study Guide makes all that 

complicated electronic the- 
ory seem simple. A little 
study with this book and 
you will be ready to face 
the FCC examiner with 
*conf idence, A $4,95 value! 



RAN 



- !■ r/> 1 »•■■• 



torn j*t 






mm 



fMll 



IIII DU9FB 



wtw EA1I0 



I I l V i " 



F1M -^ 



\H\i1 



HCSFM 



5H**C 



mm ST. 'r^r-ttmi'WM 



*V Fripi 



Bdasnu 



fVI 





E The 73 DX 
handbook has every 
OX aid you could 
hope for. . ,QSL 
Bureaus, postage 
rates worldwide, 
DXCC and WTW 
country lists and re- 
cord pages, maps of 
many areas of the 
world with prefixes, 
plus a complete 
wal l-sized world 
map with each 
book! It is profusely 
illustrated with pic- 
tures of many of the 
top DXers, plus art- 
icres on working DX 
on the different 
bands. There are 
great circle bearing 
maps and charts, 
and m ore. , .more 
, . .more. 



F The FM Anth- 
ology has reprints of 
all the articles and 
technical data from 
the early issues of 
the FM Journal, No 
FM library is com- 
plete without this 
data, much of it just 
not available else- 
where. $5.95 value, 

G The BEST of 

FM is a compilation 
of the best articles 
that appeared in the 
FM Journal from 
March 1968 through 
June 1969, the last 
of the magazine. 
Read the extremely 
controversial Chron- 
icles of 76, Plus do- 
zens of technical 
and circuit articles 
available nowhere 
else* $4.95 value, 

H Transistor Pro- 
jects for the 
Amateur is cram- 
med with over 40 
interesting construc- 
tion projects cover- 
ing receivers, con- 
verters and transmit- 
ters, many in the 
VHF region. If you 
like to build you 
will blow your mind 
over this book. 



90 



73 MAGAZINE 






GET ONE BOOK FREE WITH EACH DIFFERENT SUBSCRIPTION. 
GET THREE BOOKS FREE WITH EACH LIFE SUBSCRIPTION. 

Accept ONE BOOK FREE with our compliments for each different $6 subscription you enter. Free 
Gift Books can be sent to each subscriber or to the donor, One gift book per $6 subscription, wherever 
they go. All subscriptions will be entered to start with February 1972 unless otherwise noted. On 
renewals or extensions of subscriptions please include the address label from the magazine wrapper or 
renewal notice. This offer good in North America only. Foreign readers may participate by adding one 
extra dollar per one year subscription. 

Offer expires April 30, 1 972 

Please enter subscriptions for the following, starting with the current 1972 issue. 



That's right, ad you have to do is buy 
a one year $6 subscription to 73 and you 
are eligible for a free book (postpaid) of 
your choice or a set of back issues (FOB 
73 HQ), You say you want two books? 
Fine, no trouble whatever, just buy a 
little old gift subscription for a friend or 
DX buddy and ask us to send you the 
book or back issue package, 

Can you buy two years for $12 and 
get two books? No, sorry about that, but 
the whole purpose of this unusual offer is 
to increase the circulation of 73, not to 
just give away a few thousand books free 
of charge. We know that once an active 
amateur starts reading 73 he has a hard 
time ever being without it again and so, 
though we pay dearly for that first 
subscription, we eventually make it up 
come renewal time, And keep in mind 
that the more subscribers we have for 73 
the better magazine we can give you. 

Over 3000 great articles have appeared 
in our back issues and most of them are 
just as good today as the day they were 
printed. You will have the time of your 
life reading all those wonderful issues you 
missed, We have separated the back issues 
into three packages, issues from 
1960-1964 (1), 1965-1967 (II), and 
1968-1970 (III). These back issue 
bundles are put together by illiterate 
apple pickers borrowed from other ham 
magazine staffs and thus there is no 
possibility of our guaranteeing any parti- 
cular issue in your bundles . , . you take 
pot luck. Due to the $12 value that we 
are making available in these back issue 
packages (12 different back issues in each 
package), we must ask that you foot the 
shipping charges. Please include $1 to 
cover handling and mailing of these great 
big packages of back issues. 

If you prefer that we send a book or 
back issues to your buddy along with his 
subscription, just indicate this on the 
form. 



73 Magazine, Peterborough NH 03458 
New □ Renewal or Extension D 



Name 



Call 



Address 



City, 



.State, 



ZIP. 



Circle book wanted: ABCDE FG H I II III 

1 year $6 D choose book Life S73Dchoose any 3 books 



| 73 Magazine, Peterborough NH 03458 

New □ Renewal or Extension □ 



Name 



Call 



Address, 



City. 



State. 



ZIP. 



Circle book wanted: A B C D E F G H I II III 

1 year $6 □ choose book Life $73 D choose any 3 books 



Y 



73 Magazine, Peterborough NH 03458 
New □ Renewal or Extension □ 



Name 



.Call. 



Address 



City 



State 



-ZIP. 



Circle book wanted: A B C D E F G H I II III 

1 year $6 □ choose 1 book Life $73 □ choose any 3 books 



73 Magazine, Peterborough NH 03458 
New D Renewal or Extension D 



Name 



-Call 



I Address. 
I City 



State 



ZIP. 



Circle book wanted: ABCDEFGHIIIIII 

1 year $6 d choose 1 book Life $73 Q choose any 3 books 



APRIL 1972 



91 



M 




INDUSTRIES 

INC. 




crystal s v u» 8a . 



* 



+ .0025% guaranteed tolerance 



72 HOUR SERVICE ON 
10 CRYSTALS OR LESS 



•" 




— ^ 



*For most standard FM sets — Re- 
gency — Clegg — Drake —Swan — 
Sonar — Telecomm — Tempo — 
Varitronics — IC-21 — Johnson. 
Standard & Gladding add $1.00 ea. 



W 



Dealers! Write for our special Distribution Price Program. 



INDUSTRIES 
I INC. 



Post Office Box 508 
919 Eighth Street 
Prague, Oklahoma 74864 



PHONE - (405) 567-2286 



Please rush the following crystals to: 
IVI.O. or check enclosed for full amount 
For postage and handling add 1 —5 crystals 
25d;6-10 45d CITY 



NAME.. . 
ADDRESS 



STATE 



ZIP. 



*HC-25 Miniature/HC-6 LARGE 






Quantity 


*Holder 


Channel 
MHz 


Crystal 
Freq. 


Equip, 
Make and Model 





























































































92 



73 MAGAZINE 



EQUIPMENT REVIEW 



TESTING THE 
COMCRAFT CTR-144 




Can an FM nut live comfortably with a 
tunable receiver and a vfc transmitter? 

As an old time two meter addict my 
hands began to shake with anticipation as I 
plugged in the new Comcraft transceiver, 
just looking forward to being able to tune 
the receiver dial and get back to the old 
familiar concept of frequency being marks 
on a slide rule dial instead of numbers on a 
switch. 

Sure enough, as I tuned from 146.5 to 
147.0 there were all the repeaters, blasting 
through. And even though this segment of 
the two meter band takes up only about 
3/8*' of the dial, I still could identify most 
of the repeater channels by their position on 
the dial. The receiver was quite sensitive and 
I was able to hear repeaters right on down to 
New Haven, some 1 50 miles or so away. 

The most exciting discovery was that 
"secret** repeater up in Manchester (NH) up 
above 147 MHz. I knew their input frequen- 
cy, but had not been able to get them to 
spill the beans on the output so I could get 
crystals and their promises of getting crystals 
for me had been dragging on for a couple of 
years, so when I tuned across the repeater 
output I let out a whoop and zeroed in the 
Comcraft vfo and called in. There was a 
stunned moment of silence and then they 



acknowledged me, I didn't tell them how I 
found thenx 

The vfo is stable enough to work through 
FM repeaters with no problem. My counter 
shows it to hit within 25 Hz or so each time 
it is keyed! There are three internal crystal 
positions plus a front panel jack for a fourth 
crystal position. The rig uses the very popu- 
lar 8 MHz FT-243 type crystals, which are 
still around by the thousands from WW II, 

The CTR-144 is basically an up-to-date 
solid state Communicator. It tunes from 
144—148, with enough overlap to bring joy 

to the MARS and CAP enthusiasts. My unit 
tuned from 144,00 to 148 J 5 on both 
receiver and vfo> but this could be easily 
changed enough to add or subtract a half 
MHz or so by touching the band-setting 
capacitors. 

The power supply is built in for 1 17V ac 
operation, plus the usual 12V dc power cord 
for mobile use. A little battery test button 
on the front panel lets you check the battery 
condition. This test button may not be of 
great interest for mobile applications, but if 
the unit is used in conjunction with the 
accessory CBP-12 Comcraft battery pack, it 
will tell you how things are going. This 
battery pack is automatically recharged by 
the ac supply, by the way. 






APRIL 1972 



93 



2 Rigg in one 



THE COMCRAFT CTR-144 





MADE IN U.S. A 



The First AM-FM 

Solid-State Transceiver 

For Two Meters 

No longer is it necessary to choose between 
AM and FM on two meters. Now you can have 
both in one compact unit. Join the gang on 
the new FM repeaters yet still be able to "rag 
chew" with old friends either AM or FM any* 
where in the two meter band. 

COMPARE THESE FEATURES 

TRANSMITTER: 

■ Built>in VFO (Frequency converted for stability) 

■ AM and FM both crystal and VFO 

■ Four transmit crystal positions (8 MHz) 

■ 12 watt input AM and FM 

■ High level transmitter modulation on AM 

■ Bandpass coupled transmitter requiring only final tune 
and load 

■ Three internal transmit crystal sockets with trimmers 
for netting 

■ One transmitter crystal socket on the front panel 

■ Deviation limiting 

■ 146.94 MHz crystal included 

RECEIVER: 

■ Double conversion 

■ Crystal controlled first conversion 

■ MOS FET receiver front-end 

■ Integrated circuit limiter and discriminator for FM 

■ Envelope detector and series gate noise clipper for AM 

■ Built-in squelch for both AM and FM 

GENERAL: 

■ Separate transmitter and receiver tuning 

■ Built-in 115VAC power supply 

■ Direct 12VDC operation for mobile or portable operation 

■ Optional portable rechargeable snap-on battery pack 
available 

■ "5" Meter also used for transmitter tune up 

■ Military style glass epoxy circuit boards 

■ Anodized lettering and front panel 

■ Baked epoxy finish on the cabinet 

■ 47 transistors, 22 diodes, 1 integrated circuit 

■ Dimensions: lOW'W x 6M"H x 7 l / 2 "D 

Warranty — 90 Days Parts and Labor 



MMiww^wa 1 1 1 in i ii in ii 



The CTR-144 is available at your 
DEALER 

COMCRAFT COMPANY 

P.O. BOX 266— GOLETA, CALIF, 93017 

Write for more information or 
use READER SERVICE 




The receiver gets its selectivity and rejec- 
tion of images by a clever system of i-f 
management. The first local oscillator is at 
65 MHz and is crystal controlled. This 
doubles to 130 and the output is in the 
14—18 MHz range which is tuned by the 
first i-f. The second local oscillator drops the 
i-f to 2 MHz and then the signal is channeled 
into either an FM or AM detector, 

The 65 MH2 oscillator is used by the 
transmitter to beat the 7—9 MHz vfo up to 
72—74 MHz. This is then doubled to the 
output frequency. 

While I find a counter quite helpful in 
putting the CTR exactly on a repeater input 
frequency, I have had little trouble zeroing 
in just by listening for the repeater squelch- 
tail and tickling the vfo dial until I hit the 
pass-band. While visiting New York I cut a 
19" length of coathanger and stuck it into 
the antenna conductor, zipped onto 
WA2SUR's input on 146.19 and found 
myself talking with a number of old friends. 
This was from my livingroom in Brooklyn 
about five miles away! 

While I appreciate the benefits of chan- 
nelized operation as much as anyone, I do 
have to admit that I like it a lot that I can 
now tune the 144 MHz band complete and 
check to see what is going on. And who can 
afford all the crystals it takes to get all of 
the repeaters? With new repeaters coming on 
the air by the week, who can keep up with 
it? I'd be ordering more crystals every week 
and, at $4 to $6 each, this is a luxury 
beyond the means of a mere magazine 
editor. 

One thing I did learn from being able to 
tune the entire 144 MHz band . . . the FM 
activity is just about the only activity that 
Vm going to hear up this way. I may be able 
to get into seventeen FM repeaters from my 
home, but I have heard one and only one 
AM signal on the band in several weeks of 
listening, I haven't had a good chance to 
tune the entire band since my NC-300 
receivers were swiped a few years ago. The 
band sure has changed ! 

The Comcraft CTR-144 may not meet 
the demands of the purist F'M old timer, but 
it sure does do its job well and is a lot of 
fun. And it will run AM if you need it! 

...W2NSD/1 



94 



73 MAGAZINE 




me 

5&Z&6 



lb/71, 



PBI 

sa/as 




LOOKING 



BOCA 







Jeffrey R. Harrow WA4RLG 
1336 S, Biscayne Pt. Rd, 
Miami Beach FL 33141 



I'm not all that old (22) and yet, as f look 
back about six years it seems an im- 
mensely long time ago thai Glynn WA4LHK, 
Bill WA4MKD, myself, and the rest ot the 
renowned N.O.M.A.R.C group put on (to 
my knowledge) the First amateur two meter 
repeater in Florida, It consisted of a pre- 
prog, G.E. into two ground planes up about 
five stories — and we were ecstatic with a 
one to two mile range. 

Well, as you can see from the sketch, 
Florida took to two meters with a ven- 
geance. So much so, in fact, that for the past 



couple of years, a problem pretty old to the 
California and New England areas has be- 
come evident. With so many repeaters in 
operation, and with about 90% of them on 
34/76, we had the old problem of high 
powered base stations in Tampa keying the 
Miami repeater, and vice versa. After a while, 
the Melborne repeater came on, and later 
was joined by the Boca Raton machine, 43 
miles north of Miami, It got to the point 
where most people were shutting off their 
receivers because they were having to listen 
to too many one-sided conversations not 
meant for them. 



APRIL 1972 



95 




THE 

NOVICE 



Bfrthe 




MicroComm, 
recognizing the inalienable rigljt to QSY, 

frertomtoworkDXand mbeprnbcnrc 

to throw your crystals away, DO OfDtUU 11)10 
rStabllSl) the Novice NVX-1 Variable Crystal 
Oscillators. Fully approved by the VEL-QHSttltU" 
ttOtl and the FX.C. 

The NVX-1 works like a V,F.O. with your XMTR. 

Coverage: 3702-3748 KHz 
7152- 7198 KHi 

Declare your Independence and order today at the Intro- 
ductory Price $39.75, p.p.d., wired. Guaranteed and certified 
for one full year. California residents add 5% sales tax. 



CPHMUMCITA4 



| ■ I |4- 



— ■ 

.1 I-B-Ul II l| 

I 




Available ONLY factory direct from: 

*\ . « the birthplace of new ideas 
in Novice Communications" 

BOX 373 

CUPERTINO, CALIF. 
95014 



Then, about eight months ago, the 
Orlando repeater came on in the center of 
the state. Poor Melborne. Poor Tampa. 
Orlando base stations were consistently key- 
ing up their repeaters with 20 dB to full 
quieting signals, Melborne even changed 
their receiver antenna orientation to reduce 
the problem (and in doing so, though, they 
removed repeater coverage from a rather 
barren stretch between Orlando and Mel- 
borne, a nice place to have a flat tire). At the 
same time down in Miami, the Boca repeater 
was going strong. It put usable signals into 
Miami, and communications took on quite 
an interesting assortment of squeals, grunts, 
and shouts of "Hey, control station, please 
shut this &S##% machine down so I can talk 
to Boca," 

Up to now Eve described a situation very 
familiar (or it may soon be) to most of you. 
Here is the solution that the South Eastern 
Repeater Association committee, headed by 
Hal Greenley K4GYO, proposed, and which 
was adopted by all of the S.E.U.S, repeaters: 

On January 15, 1972, all of the S.E. 
repeaters changed their main input frequen- 



cy to either 146,16, 1 46.22, or 146:28 MHz. 
The specific frequency allocations were 
made by the committee, based on. factors 
including location, seniority, adjacent re- 
peaters, etc. These inputs are "open/" that 
is, no tone coding of any kind. Each repeater 
also maintains a 146.34 MHz input. This 34 
input is Touchtone coded with a different 
code assigned to each repeater. The code 
performs a latching function (at the discre- 
tion of each repeater) or a lime delay. Eor 
instance, if the Miami repeater 34 input 
hears a digit one, it will open, and leave 
open, the 34 input of the machine, until it 
hears another digit one, when it will close 
the 34 input. The 16, 22, or 28 inputs will 
have priority over the 34 input. So if a 
station comes on 16. the 16 station will take 
over, or capture the repeater, even if a 
station is already transmitting on 34, 

Several months later, each repeater will 
change its output frequency to 146,76, 
146.82 and 146,88 MHz respectively. 

Now, what have we gained from this 
mildly expensive and time consuming area- 
wide change? 



96 



73 MAGAZINE 



First of all, by careful frequency assign- 
ments, mobiles using one repeater will 
not - under normal conditions - be able to 
key up the closest repeater using the same 
channel. Notice that 1 said mobiles. What 
about base stations? 

All base stations will be requested to use 
the 146.34 inputs. This serves several pur- 
poses- First and foremost, it allows a mobile, 
any mobile, and even an HT, to break into a 
chat by a base station to request help, report 
accidents, etc. (Remember our justification 
for existence - public necessity, interest, 
and convenience.) Secondly, it allows high 
powered base stations in Miami for instance. 
to talk through the Orlando repeater with- 
out keying up, or tying up other repeaters 
around the state. Toward this end, all the 
individual repeater need do is to keep its 34 
input tone coded off when not in use. The 
repeaters with 34 coded off will not be 
bothered by the long haul conversation. Of 
course, two cross-state conversations at once 
could pose a problem, but then nothing 
(yet) is perfect. I might also point out that 
traveling mobiles who can't cram in two 
more sets of crystals can utilize the 34 input 
of any repeater he is near with his Touch- 
tone pad. The only disadvantage for mobile 
use of 34 is that several repealers will only 
operate one centralized 34 receiver while 
they may have several satellite receivers on 
their main discrete frequency. Third, if more 
areas conform to these standardized chan- 
nels (and they are), only three sets of 
crystals will be necessary to cover most of 
the country. Rick WB4IHS, and I recently 
took a light plane trip from Miami to San 
Francisco and back; we know we missed 
more repeaters than we worked. Also, the 
many combinations of PL tones described in 
several magazines won't be necessary. 

This is the beginning of the standardiza- 
tion which is so necessary to our continued 
expansion. This plan, which you notice 
incorporates 600 kHz spacing between the 
repeater transmit and receive frequencies 
allows more practical one-site repeaters. 
Another not so obvious advantage is that 
standard 600 kHz spaced, 60 kHz staggered 
channels make frequency synthesis some- 
what easier to produce. 



Certainly there are some objections and 
disadvantages to this plan. The most often 
heard seems to be the expense of the new 
crystals and the fact that "We were here 
first, why should we move?" Well, the 
expense, especially in the field of ham radio, 
is rather minimal. It is interesting to note, 
however, that most forms of improvement 
and progress cost some money. This isn't the 
first and certainly not the last such instance, 
To the other objection, that of "squatters' 
rights," I say this: Each motorist on the road 
has given up some of his freedom - such as 
having to stop at a traffic light when he is in 
a hurry. To go further, the nations of the 
world have given up some of their free- 
doms - such as not indiscriminately testing 
nuclear weapons. This giving up of ^rights" 
is done in order to bring about the greater 
good of all. The same thing holds true here. I 
read a very disturbing article recently where 
a group of irate two meter hams had a 
repeater evicted from a beautiful mountain 
top site because it was bleeding into their 
receivers 30 kHz and ten miles away. At this, 
I can only shake my head. 

All in all, two meters is growing; well in 
some areas, and poorly in others. If we all 
give just a little we may one day see a 
beautifully interlinked repeater system not 
only in Florida but extending toward the 
rest of the country with autopatch facilities 
and possibly I AX or TV. Atlanta and 
Florida are even now beginning to talk of a 
link!. And remember, amateur satellites can 
do more than broaden our horizons - they 
can literally jump them! 

Repeaters are becoming more prevalent, 
and with a consistent, carefully planned 
system* each repeater will be covering a 
larger and larger area without bothering its 
neighbor. And remember, if the FCC re- 
ceives many complaints from irate repeater 
groups they could justifiably impose their 
own rules. We have traditionally been a 
sell-policing group, and it would behoove us 
to retain this system. 



The future? Its governed by what we do 
today! Remember how the fantastically 
complex Bell system started. 

. . .WA4RLG 



APRIL 1972 



97 



■PHI 



«l 



mmmmm* 



warn 



IF YOU'VE 




USED 







REPEATER, 



r 



If you haven't 

already received 

a copy of our NEW 

■ 

1972 Catalog of Precision 

Quartz Crystals & Electronics 

for the Communications Industry, 

SEND FOR YOUR COPY TODAY! 







Somewhere along the tine, in vir- 
tually every ham repeater in the 
world, you'll find a couple of Sentry 
crystals. 

Repeater owners and FM "old- 
timers" don't take chances with 
frequency— they can't afford to. A 
lot of repeater users depend on a 
receiver to be on frequency, rock 
stable.. Jn the dead of winter or the 
middle of July. The repeater crowd 
took a tip from the commercial 
"pros" a long time ago— and went 
the Sentry Route, 

That's one of the reasons you can 
depend on your local repeater to be 
there (precisely there) when you're 
ready to use it. FM'ers use the 
repeater output as a frequency stan- 
dard. And for accuracy, crystals by 
Sentry are THE standard. 

IF YOU WANT THE BEST, 
SPECIFY SENTRY CRYSTALS. 



Ask the Hams and Pros 

Who Build Repeaters/" 



YOU'VE USED A 






SENTRY MANUFACTURING COMPANY 

Crystal Park, Chickasha, Oklahoma 73018 

PHONE: (405) 224-6780 

TWX -9 10-830 -6425 



EQUIPMENT REVIEW 




Ed Webb W4FQM/1 
Technical Editor 
73 Magazine 



Ross 
and 

White 
RW-Band Tranceiver 



Tlhe Ross and White RW-Bnd 2 meter FM 
transceiver is one of the newer entries 
to the FM market place, and it brings with it 
several unique features. 

You can put it in your glove compart- 
inent, it is so small. The front panel mike 
socket lets its trim design slide into narrow 
places, like the empty hole in your dash- 
board where the AM radio used to be. If you 
prefer to keep it outside, you can mount it 
underneath the dash or on the transmission 
hump with the mounting bracket that is 
included. And this rig is portable too. You 
can use it with a shoulder strap and flash- 
light batteries. Its size is deceptive because it 
is loaded with features. Keep reading. 

The little knob at the side is for the 
built-in tone burst encoder. More and more 
repeaters are requiring tones to activate the 
transmitters and other functions of the 
repeaters, such as low band links. In some 
areas that have several repeaters with the 
same input frequency, a different tone is 
required to turn on each particular machine. 
Other rigs require externally connected 
boxes that have the tone generators inside. 
The generator is already inside the RW-Bnd. 

These tones are easily reached for field 
adjustment and the three switchable posi- 
tions should be sufficient even for the 
frequent traveler. Since the tone circuits use 
ICs, they are trouble free and should require 
no maintenance at all. 



You will notice that there are four knobs 
on the front panel. There is a volume and a 
squelch control as with all others. To turn it 
on, you turn on the volume and adjust it for 
a comfortable noise level with the squelch 
open. Right? Wrong. Once you have adjusted 
these two controls you should not need to 
adjust them again because the main power 
switch is included in the power level switch. 
There are three power levels (piys 'off') that 
offer a variety of operating conditions. The 
low power slot is fine for talking to the 
mobile who is following you. No need to tie 
up a lot of other people on the direct 
channel. The medium power level is perfect 
for keeping in touch with the base when you 
head out for a loaf of bread- Incidentally, 
these two levels are satisfactory for portable 
operation using batteries or other situations 
where low current power suplplies only are 
available, such as when you are on a business 
trip. The usefulness of this rig for emergen- 
cies is self-evident; low current drain, buUt in 
tone burst, and small size. If there is no 
emergency and you are just talking to the 
distant repeater several cities away, the high 
power position is the ideal level as this 
allows the rig to run ten-plus watts output to 
the antenna. 

Do you have visions of plugging your rig 
in and pushing the mike button and watch- 
ing the relative rf output meter quickly flash 
to maximum and then crashing to zero? This 
will not happen with the RW-Bnd because it has 



APRIL 1972 



99 



a protection circuit that prevents the final 
transistor from blowing out if the swr is too 
high, such as when you forget to connect the 
antenna or a low tree branch takes it off. 

The circuitry is modern and of advanced 
design. For example, the transmitter uses an 
IC oscillator. Most other rigs do not have an 
IC here. In the receiver, the sharp i-f does 
not block or get cross-talk from adjacent 
channels. Once inside the rig, you will notice 
that there is a lot of room. You will be 
grateful for this when you try to change 




2502 Township Line Road 
DREXEL HILL, PA 19026 

FOR THE PRICE of a RIG! 




• SBE SB-144 FM TRANSCEIVER 

• MOSLEY 5/8 wave ANTENNA 

• LATEST REPEATER ATLAS (1972) 

• 1972 ARRL Handbook 

• 20 ft. RG-58/U coax 
with connector 

ALL FOR ONLY $239.00 

Major Credit Cards A ccepted 
Vince Barr, Mgi\ Ben Schaefer 

WA3ICS WA3ATP 



crystals for the transmitter or receiver be- 
cuase there is room to get a couple of fingers 
in there and you do not have to use a pair of 
pliers that might pinch the crystal. Each 
rock has a trimmer capacitor to let you get it 
exactly on frequency, transmit and receive. 
Twelve channels are sufficient for most areas 
and this is what you have in the RW-Bnd, In 
case one of your local repeaters has not 
switched to the standard 600 kHz spacing, 
crystal jumpering is easy. 

Once the rig is installed, the clear, clean 
and plentiful audio will strike you. The front 
mounted speaker is what does it. The audio 
is not directed at your feet nor is it muffled 
in the maze of wires behind the dashboard. 
You will not need to hook up an external 
speaker to hear this one, Another useful 
feature is the accessory jack on the rear 
panel. It is 1 connected to nothing. Your own 
needs and imagination are the determining 
factors here. Do you use a Touchtone pad? 
Tie it in here. Do you use a continuous tone 
squelch system (PL)? Attach it to this plug. 
Perhaps you want to run the audio output to 

another speaker in the rear of the car. It is 
easily done. You can even bring out test 
points for monitoring the functions of the 
rig. 

One other valuable contribution the Ross 
and White people have given the ham for 
maximum enjoyment of his FM rig is a 
complete instruction manual. Book is a 
better word to use. It has pictorials, parts 
placement pictures, voltage tests, operating 
theory, and more. It is a valuable volume for 
the proud RW-Bnd owner. 

For more information about this great 
rig, contact Ross and White at 50 West 
Dundee Road, Wheeling IL 60090. . . .Staff 



FIAM Electronics^ 

P.O. Box 3062 ^ ) 
Wilmington, N.C, / / / 
284&1 / 
How to Order: 
Send Check or M'Ol 



Patent 

Applied 
For. 




Send for: 



3 Watt 
Audio Amp 



SSB or CW 
Transceiver 
SINE Wave 
TONE GEN. 



AM & SSB 
TRANS- 
CEIVER 



ELD INTENSITY AMPLITUDE MODULATION 
/ ) Amateur Do-lt-Yourself 

Directive Displacement Modulation 
Guaranteed FIAM Specifications: 

1, The^only known modulation system that is compat- 
ible with AM & SSB. (When Receiver is corrected as 

recommended.) 
2* Uses the same FIAM control unit for 6 thru 20 m. 

Yagi Antennas. 
3. Tests indicate less cross talk. 

1. Free typical FIAM Receiver Adaptation details. 
Postage , $ .10 

2. FIAM Construction 8t Operation Manual. (Postage 
Included) , $ 1.25 

3. 2 Modulation Control units 36.95 

4. Postage & H,C. for item 3 50 

5. Additional components (purchased from others). 40.00 



100 



73 MAGAZINE 



FROM JIM, WN5C0Z 



NOAA Studies 

Ionospheric 

Effects 
Thunderstorms 

Reprinted from Collector and Emitter, a 
publication of the Aeronautical Center Ama- 
teur Radio Club of Oklahoma City, Okla- 
homa. 




Scientists of the Commerce Department's 
National Oceanic and Atmospheric Ad- 
ministration have found that thunderstorms 
transmit tremendous sound pulses into the 
ionosphere 1 25 miles above the earth. 

By observing these high-altitude perturba- 
tions with carefully sited radio transmitter/ 
receiver arrays, the scientists have deter- 
mined that a pulse can give the ionosphere a 
three-mile lift directly above the originating 

storm. 

Dr. Kenneth Davies of NOAA's Apace 
Environment Laboratory at Boulder, Colo- 
rado, says the ionosphere begins responding 
to thunderstorms about the time their tops 
have reached the 40,000-ft level. 

The turbulence within the thunderstorm 
produces pulsations which travel through the 
atmosphere as pressure waves. Unlike radio 
waves, which penetrate the atmosphere with- 
out affecting the natural gases through which 
they pass, these pressure waves move by a 



APRIL 1 




CRYSTAL BARGAINS 



Depend on . . . 

We can supply crystals 
from 16 KHz to 80 MHz in 
many types of holders. 
Over 6 million crystals in 
stock including CR1A/AR, 
FT243, FT241, M67, HC- 
6/U, HC13/U. etc. ORDER 
DIRECT with check or 
money order to JAN 
CRYSTALS. For first class 
mail add 150 per crystal 
— for airmail, add 20C per 
crystal. Inquire about 
special quantity prices. 



n 



DIVISION Of BOB 

WHAN & SON 
ELECTRONICS, INC. 

2400 Crystal Or. 

Fort Myers 

Florida 33901 

(813) 936-2397 

Send IOC for new 

catalog with 

oscillator circuits 

and lists of 

thousands of 

frequencies in 

stock. 



SPECIALS 

Color TV crystal (3579. 545 KHz) wire leads 

4 for 
100 KHz frequency standard crystal (HC 13/U} 
1000 KHz frequency standard (HC 6/U) 
Any CB crystal, trans, or rec. 

(except synthesizer crystals) 
Any amateur band crystal in FT-243 holders 
(except 80 — 160 meters) 

4 for 

60 meter crystals in FT-243 holders 




AT LAST 

A SPEECH COMPRESSOR™* 
REALLY WORKS! 





RPC-3,3U Interna! Unit 
($24,95) 



RPC-3C Cabinet Model 
(S34-95) 




RPC-3M Module 
(ONLY $22.50} 



• Low distortion 
circuit. 

• Fully wired & test- 
ed. NOT A KIT 

• Works with phone 
patch. 

• Internal units & 
modules work mobile. 

• FULL WARRANTY - ONE YEAR 

• INTRODUCTORY LOW PRICES 

(Illinois residents add 5% Sales TaxJ 

Write for specifications and information sheets 
(Free), Demonstration Tape (cassette) available 
($2.00 deposit). 

FJ> ELECTRONICS 

Box 1201 B Champaign, III. 61820 



101 



KIRK 
QUAD INSTRUCTION MANUAL 

Thousands of quads have been 
constructed from this manual 



48 Pages of authentic 
information on cubical 
quad construction* All 
you need to know to 
build a great DX anten- 
na. Facts, methods, de- 
signs, dimensions, Q&A, 
dual and multi-element 
arrays, low band 40 — 20, 
15, 10 meter, high band 
VHF 6 and 2 meters. All 
in f o r mation supplied 
from actual constructed 
models and 20 years of 
experience* 

One of the most com- 
plete quad instruction 
manuals ever offered. 
You need this manual 
few: your library even if 
you never build a quad. 

PRICE 

USA & Canada 
Foreign Surface 
Air Mail 
All Postpaid. 



tasniucTiofl 



IEEH1E5 SUPER-QUADS 




I J * 



f*K4 LZ DC- 






$2.00 
$2.80 
$3.60 



KIRK ELECTRONICS DIVISION 

134WesTpark Road 
Dayton, Ohio 45459 

Tel: 51 3/433 -3 T 02 




CAMP ALBERT 



RADIO SESSION 



13th year - July 29 - Aug. 12th 



Courses Taught: General Theory and Code 

Advanced Theory and Code 
Amateur Extra Theory and Code 
Golf privileges at New River Country Club; also fishing 

TRUL YA VACA TfON WITH A PURPOSE!!! 

People attended from the following states and areas: 

North Carolina. South Carolina, Missouri , Tennes- 
see, Utah, Florida, Oklahoma, West Virginia, Ala- 
bama, New Hampshire, Iowa, District of Columbia, 

Vermont. Arizona, Indiana, Ohio, New Jersey, 
New York, Massachusetts, Maryland, Virginia, Illin- 
ois, Michigan, Georgia, Kansas, Mississippi, Nebras- 
ka, Maine, Kentucky, California, New Mexico, 
Arkansas, Texas, Wisconsin, Louisiana, Oregon, 
Connecticut, Minnesota, Pennsylvania, 

OUT OF STATE: 
Puerto Rico; Saskatchewan, Canada; Ontario, Can- 
ada: Quebec, Canada; Granada, Spain; London, 
England; Geneva, Switzerland; Netherlands An- 
tilles; St, Croix, Virgin Islands 



JCX. Peters, K4DNJ, General Secretary 

i Gilvin Roth Y.M.C.A., Elkin, North Carolina 

I Please send me the Booklet and Application Blank 
I for the Camp Albert Butler Radio Session. 

Name Call 



I 



Address 



i 
i 

| City/State/ 2 ip_ 
102 



1 



train of collisions between molecules along 
the path. As a molecule of atmospheric gas is 
perturbed by the pressure wave, it moves, 
striking a neighboring molecule which in 
turn moves and strikes another, 

These infrasonic pulsations originate in 
the lower atmosphere (troposphere), where 
the molecules of gas are packed densly, so 
that each molecule travels a short distance 
before striking another (less than one mil- 
lionth of an inch). As the pulsation travels 
upward to the ionosphere, the atmosphere 
thins and the molecules are farther apart . At 
an altitude of 125 miles; the molecules of 
gas are so thinly distributed that one may 
have to travel 1,000 ft before colliding with 
another. This density reduction is respon- 
sible for a 1,000 times amplification of the 
vertical movement of the atmosphere at 
ionospheric altitudes, The actual upward 
surge of the atmosphere (not the individual 
molecules, but the whole mass of air in the 
region affected by the acoustic pulse) is 
about 15 ft at cloud level and 15,000 ft in 
the ionosphere. 

Because of the geometry of the earth's 
magnetic field, the eiectronis in the ionos- 
phere behave differently from the neutral 
gases, which are unaffected by geomag- 
netism. South of the detection array, the 
atmospheric surge carries across the mag- 
netic field lines. The neutral constituent 
moves upward normally, but the charged 
electrons are restrained by the field. Because 
radio signals are reflected from the electrons 
and not the neutral part of the ionosphere, 
the movement cannot be observed. 

To the north, however, the atmospheric 
pulses move along the magnetic field lines, 
and the electrons easily move with it. Thus, 
the surge of the ionosphere can be observed 
by reflections from the mass movement of 
electrons north of the transmitter/receiver 
array. 

Observations indicate, according to 
Davie s, that when ionospheric responses to 
thunderstorms occur, the top of a cumulo- 
nimbus cloud has risen to more than 40,000 
ft within 150 miles of the midpoint of the 
radio circuit. Such responses have been 
recorded on the Oklahoma paths and on 
paths between Long Branch, Illinois, and 
Boulder, Colorado. 

73 MAGAZINE 



Reporting in the Journal of Atmospheric 
Science I March 1971) on studies of the 
ionospheric responses, l);mes and John E, 
Jones, also of NOAA's Space Environment 
Laboratory, cited two principal advantages 
of using the ionosphere to detect the pulsa- 
tions generated in the troposphere: (1) the 
density decrease with altitude in the atmos- 
phere provides natural amplification of the 
generated pulses, and (2) the atmosphere 
acts as a filter to remove unwanted acoustic 
waves. In effect, the ionosphere is a natural 
tuned receiver. The amplification is several 
hundreds to one, although interference from 
acoustic waves of unknown origin does 
occur. 

On the basis of present knowledge, it is 

difficult to relate the ionospheric measure- 
ments directly to characteristics of the thun- 
derstorm, As with any new technique, a 
considerable body of data must be gathered 
and time spent in analysis before the rela- 
tionships are understood. A 10 to 20-year 
lag between a scientific discovery and its 
routine use is not unreasonable, according to 
Davie s. 



T.V.I. PROBLEMS? 



T.V.I. Filter B & W Model 424 de- 
signed for C. B. and Ham up to 100 
watts. Input & output impedance 50 
ohms more than 60 db of attenua- 
tion of harmonics. 

Price-$10.88 

See your dealer or write: ^ 
Barker & Williamson, Inc. 




jm 



s%> 



Canal Street, Bristol, Pa. 19007 



JEPF-TRONICS 



SURPLUS ELECTRONICS 

TUBES 

PARTS 

SEMICONDUCTORS 

TEST EQUIPMENT 



TOP QUALITY - LO WES T PR ICES 
new catalog - $.25 handling 

JEFF-TRONICS 

425? Pfiarl RdL. Cleveland. OH 44109 



the 



Incomparable CX7A 





// 



CX-7A 



New "A" model Now Available 
Stilf $2195 - Great New Reliability 




Quite frankly there is nothing with which 
to compare the CX7A. What else is there 
that has all modes 10 thru 160 meters with 
instant, no tuning band changing? With true 
break-in CW, a Pre LF. noise blanker, R.F. 
clipping, and a built-in Keyer? With a sepa- 
rate receiver, wattmeter SWR meter, FSK 
shift, transmit offset and a freq meter digital 
counter? 

RELIABILITY IS NOW standard equip- 
ment Every component is instrument grade, 
hand-picked, and individually tested. The 
CX7A is Americarvmade, "Ham " tested and 
"burnt-in" by Hams who build, service, and 
sell it. 

If you want to move up to the best, 
phone DON PAYNE, K4ID, for personalized 
service, a brochure, and a KING-SIZE trade- 
in on your gear. It's perfection for $2195. 

PAYNE RADIO 

Box 525 
Springfield, Tenn, 37172 



DSVM6T5) 304 5573 



Nifms 

Sundays (615V 364-5643 



I will take $ 



Send Brochure 

for my 

Name , . . .♦ Call . 

City State . 



* * - 



You 



can 



have 



I he 



tidb 



SO n 



Omni- 



TOPfnSICNAL 

at a reasonable price. 
GAIN * Increase your effei live power without a 
power amplifier. 

* Increase your receive capability without 
I Mi' a pre -amplifier. 

* With the AT-2KM antenna. 



directional 



3 MHz Bandwidth 




AN-TEK INDUSTRIES 



Box 357 R,R, 5 
Elkhart. Indiana JB514 
$58.95 FOB Elkhart 



CLAJON fcNTI M'RISES 



Name 

St reel 
CLIy_ 



$69 y 5 FOB Carson 
Call 



SUile 



Zip 



APRIL 1972 



103 



FM as seen by. . . 



vP, 




<* 



<b 



>, 



IS J_ 



*•>'<*!& pu 



^ 

w 





The FM newcomer 



The "D-C" band operator 




WAME HERE 
IS FRED 





The El A 



i ^i*^ 



The 20-meter DX'er 



104 



73 MAGAZINE 




The mountain tops 




The repeater jammer 



H.T. (Tom) Orr W6E1F/4 
1 7A East Circle Drive 
Bay Point 
Key West FL 33040 





The Japanese manufacturer 



r 









Any other mode as seen by the FM'er 



-7 




V 



•r&e 



The FM'er 



APRIL 1972 



105 



-*■ 



TRADE 



WANTED 



OFFER . . . 



SBE LINEAR SYSTEMS 

SB-36 SSB/CW Digital alt band transeiver 500 PEP 

SD-144 2m FM Transceiver, 12 channel, 3 crystals supplied, 10 watts, and microphone 



. $895.00 
. $239.95 



. ■** rrt r 



R. L.DRAKE 

TR-22 2m FM Transceiver, 6 channels, 3.— ^^^— — i — 

crystals supplied, 12V DC, nicads, 120V AC ^|MBHIi9f ^8 B, ^^W^l A! 

cord, microphone, 1 watt $199.95 ■■^^ WF 

AR-22 Mobile 12V DC Amplifer, 25 watts out 

with TR-22 $149.95 ~~ * 

ML-2S 2m FM Transceiver, AC/DC built-in, 1 2 channel, 3 crystals supplied, microphone . $299.95 
DSR-1 Digital synthesized receiver, 10kHz to 30MHz . . , .$2,195.00 

REGENCY 

HR 2A 2m FM Transceiver, 6 channel, 15 watt output, I2V DC, microphone....... $229,00 

AR-2 Mobile I2V DC Amplifier, 32-48 watts out with HR2, 2A „„„„„.„„.„„ $119.00 

CLEGG 

22'er FM Transceiver, 25 watt output, tunable receiver, 0.3/iV sensitivity for 20 qui- 
eting . # , , , v .,,,.ii .$384.95 

TR Booster, solid state antenna pre-amp., less than 3dB noise figure more than 14 dB gain, 

negligible transmission loss . . . , $47.50 

FM 27A, fully synthesized transmit and receive, 20 watt RF output S449.95 



ROSS& WHITE 

RW-Bnd 2m FM Transceiver, 12 channel, 4 
crystals supplied, 12V DC, microphone, 10 

watts, built in tone-burst $359.95 

without tone-burst « _ $329.95 

Solid state encoder TE*2 two tone .... $39.95 
Sotrd state encoder TE-5 five tone .... $49.95 



'/ 






TRADE-INS TAKEN ON 

Collins, Drake, SBE, Hammarlund, Swan, Clegg, H.T., Tektronixs, General Radio, and Quality 
Military Surplus receivers. Airborne and ground radios, military test set. 



sup immmics no. 



Write - Wire - Phone 



(813)722-1843 



2412 NORTH HIGHWAY 301, ELLENT0N, FL 33532 



106 



73 MAGAZINE 



CIRCUITS, CIRCUITS, CIRCUITS. 

The following circuits have appeared in the referenced books, magazines, application notes, etc. 
While we try to reproduce all of the information that should he needed by an experienced construe lor t 
readers may want to avail themselves of the original sources for peace of mind. 

Readers are requested to pass along any interesting circuits that they discover in sources other than 
U.S. ham magazines. Circuits should be oriented toward amateur radio and experimentation rather 
than industrial or computer technology. Submit circuit with all parts values on it, a very brief 
explanation of the circuit and any additional parts information required, give the source and a note of 
permission to reprint from the copyright holder, if any, and the reward for a published circuit will be a 
choice of a 73 booh. Send your circuits to 73 Circuits Page, 73 Magazine, Peterborough NH 03458. 



I MHt 30 pF 

hQi — #- 

ui 

SN 7400 



PHOTOCELL 




r 



Vfcc 



Vte 



Vbc 



Vet 



7 


1 


^^ 


3 




II 


6 






2 


U2 




K> 




r4 


3 


12 





SENSITIVITY 



MHz 




■o**"o- 



| — ON.C. 

j* — ON.O. 



"="9 VDC 



RELAY 
6 VDC 



I 

2 

5 

3 
6 
7 



14 

fZ 
II 



9 
8 



Vtc 




Turn anything on — or off — with light Use it to 
trigger an alarm, to turn on lights at dusk, activate. 
a counter as people pass. , .or whatever. Easy-to- 
build versatile circuit courtesy of Calactro Hand- 
book. Transistor is a Calectro JC4-505. 



SN 7400 
TOP VIEW 



Rl, R3 I.9K 

R2 t R4 t ftS IK 

UI SN 740O QUAD 2HNPUT HAND GATE 

U2, U3 SN 7490 DECADE OOUNTWS 

Vcc 3 VDC 

This crystal calibrator has a fundamental 1 MHz 
crystal and its frequency is divided to give outputs 
of 1 MHz, 100 kHz and 10 kHz. All the parts used 
are easily available from Polypaks, HAL Devices, 
etc., for a small fee. Circuit courtesy of Zero Beat 
(Victoria BC) for November, 1971 




out 



cc 



CI-CS 0.1 jiF 




I0O0 






FM04JIMCV-MMI 



Two stage video amplifier with AGC control of 1C gain and no tuned circuits required. The curve 
shows the video amplifier response with AGC. This circuit from Motorola HEP Radio Amateur's IC 
Projects HMA-Z6, available free from Motorola, DepL 73, Box 20924, Phoenix AZ 85034. 



APRIL 1972 



107 



— 



+ 19 VOC 



\ 



100 yF <IM 



C2 



H^i 



rh 



R4 
fOK 



u1* L 




»0 tfF 



SENSITIVITY FOR 

mV 


CI 
pF 


C2 
pF 


R| 
*, OHMS 


R2 
OHMS 


R3 
OHMS 


OHMS 


p o 
w 


600 








to 


I.OK 


62 


16 


2.0 


15 


100 


IO0 


SI 


10O 


2.2K 


ts 


2.0 









v+ 



IK 



1-0 JiF 

is- 



C3 



R4 
tOK 



TO PIN 5 



k 



500 pF 



6 

TO PIN 3 




A typical circuit application utilizing a Motorola MFC9010 monolithic functional circuit, which is a 
2-watt audio amplifier designed to provide the complete audio system in TV, radio and phonograph 
equipment. Schematic at right shows alternate connection to permit connecting speaker to ground 
instead of to V+. Circuit courtesy Motorola Functional Cfrcuits handbook. 



' O o K. 



U— SO 



O o 



22K 



68K 



50j*F 

12V NPN 



100 pF 
12V 




_=_9 VDC 



SPKR 
4ft A 



Another Calectro circuit, this one a screaming 
siren. Tone rises and falls like the big ones. Circuit 
courtesy Calectro Handbook (50<j) t 400 S, Wyman, 
Rockford IL 61101. Ql is a Calectro K4-S06, Q2 a 
K4-505, SI is a push button switch. 



CI 
OJjjF 

(OPTIONAL) 
INPUT D [(■ 



f\ 




OUTPUT 



ALL CAPACITORS- 15V 
ALL RESISTORS- 1 /2W 



ffil 



osr 

NO, 43 

m l»fliW 



1 15V -P\ 



60 Hz 




8 »F 

200 V 
Non-Polar 



TWO 6-VOLT BATTERIES IN 
SERIES CONNECTION, 



Simple ni-cad battery charger circuit from FM 
Magazine, as reprinted in The Best of FM, an 
anthology of articles from FM Magazine published 
by 73 and available from 73 Magazine, Peter- 
borough NH for $4.95- 



+9V 



RETO 




Audio amplifier. This circuit has a high impedance 
input, low current drain (0.2 mA), low impedance 
output, wide range (10 30,000 Hz) and a gain of 
200 to 400. Circuit courtesy Motorola HMA-33 
Tips on Using FETs. 



Power failure indicator. Indicates either moment- 
ary or continuous power failure. Circuit courtesy 
Motorola Semiconductor Power Circuits Hand- 
book. When circuit is reset it will trickle charge the 
battery, keeping it at full charge. 



108 



73 MAGAZINE 



S2Sim& 



m& 




mmw 




STUDY GUIDE 



Questions & Answers Part 



The Extra class amateur license is the 
highest rank of License offered, and as 
such demands the greatest knowledge of 
radio and electronics theory and practice 
(in fact, the Extra class exam requires at 
least as much knowledge as does the First 
Class Commercial Radiotelephone license 
with radar endorsement, generally accepted 
as being the most demanding of all FCC 
exams). 

Because of the greater requirements of 
the Extra class license, its official study list 
of questions is the longest and most de- 
tailed of all the FCC study lists, totalling 
90 questions. For comparison, the General 
class study list contains only 52 questions 
and the Advanced class has 65. What's 
more, the Extra class questions frequently 
call for detailed discussions of the subject 
rather than simple one-sentence replies. 

Because of the greater detail and larger 
number of questions to be covered, we've 
divided the Extra Class Q&A portion of 
this license study course into two sections 
of 45 questions each. This section contains 
the first 45 questions, with our answers. 
The next one will contain the remaining 
questions, 46 through 90, 

We must emphasize that this is merely a 
checklist which you may use as a "final 
exam" to test your readiness for the Extra 
class exam. Explanation of the material has 
been held to the mimimum; for details, 
refer to the Extra class study series pre- 
viously published in 73 Magazine, or our 
reprint of the series. 



L What are sideband frequencies? Dur- 
ing 100% sinusoidal amplitude modulation, 
what percentage of the average power is in 
the sidebands? How is the sideband power 
related to the percentage of modulation? 

A. Sideband frequencies are those fre- 
quencies contained in the "sidebands" of a 
modulated signal. The sidebands consist of 
frequencies above and below the carrier 
frequency, which correspond to the sum of 
carrier and modulating frequency, and the 
difference, respectively- If the carrier is 
modulated by a single frequency, the side 
frequencies will also be single frequencies. 
If the carrier is modulated by a band of 
frequencies (as is usually the case, for voice 
transmission) the sum and difference sig- 
nals become bands also, accompanying the 
carrier. 

During 100% sine-wave AM, one-third 
of the average envelope power (total signal 
power) is in the sidebands and two-thirds is 
contained in the carrier* That is, the 
sidebands contain half as much power as 
the carrier. 

Modulation percentage is based on a 
voltage measurement, Power varies as the 
square of the voltage, so the power content 
of the sidebands will vary between and 
1/3, proportionally to the percentage of 
modulation as it varies from to 1 00, 

2. What do the modulation envelopes of 
amplitude-modulated waves with 75%, 
100%, and greater than 100% modulation 
look like? 



APRIL 1972 



109 



A, Refer to Fig. 1 for views of the 
modulation envelopes. 




75% 



100% 



OVER 100% 



3. How may a li miter be employed in an 
FM receiver? 

A, In an FM receiver, the purpose of the 
iimiter is to remove all amplitude variations 
from the received signal, thus reducing 
atmospheric noise (which consists pri- 
marily of AM components), 

4. What precautionfs) should be taken 
when measuring the rectified grid voltage 
in an oscillator with a dc voltmeter? 

A. For the protection of the voltmeter, 
all rf energy should be blocked from 
reaching the voltmeter by use of an rf 
choke in series with the voltmeter "hot" 
lead. To assure that oscillator operation 
suffers minimum disturbance, a high- 
impedance voltmeter should be used, and 
care should be taken to avoid introducing 
stray capacitance* 

5. What is meant by frequency shift 
keying and how is it accomplished? 

A. Frequency shift keying (FSK) is a 
form of modulation usually used in RTTY 
operation in which the "mark" condition is 
represented by a signal at one frequency 
and the "space" condition is represented 
by a signal at another frequency. One of 
the two signals is always present, but they 
are never present simultaneously, 

FSK is usually accomplished by switch- 
ing a small capacitance into and out of the 
oscillator resonator circuit , to produce the 
lower of the two frequencies when the 
capacitor is in the circuit, and the higher 



when it is out of the circuit. This switching 
is frequently accomplished by diodes. 

6. Why is there a practical limit to the 
number of stages that can he cascade if to 
amplify a signal? 

A. The amount of amplification which 
can be applied to any signal is limited by 
the unavoidable electrical noise introduced 
both by the early amplifying stages, and 
present with the signal when it enters the 
amplifier. 

The final limit is reached when the noise 
that accompanies the signal at the input to 
the amplifier is the controlling factor, 
"Low noise" amplifiers are designed with 
the intent of reaching this limiting condi- 
tion, and it can be reached in practice at all 
frequencies in normal use, from the audio 
range through SHF, 

Certain techniques of "coherent detec- 
tion" make use of a prior knowledge of the 
nature of the expected signal to dig into 
the accompanying external noise for the 
signal. Such techniques, for instance, make 
possible radar measurement of the distance 
from Earth to Venus, and are used in many 
types of communications. Even these tech- 
niques, though, are ultimately limited by 
the random and unpredictable nature of 
background noise, 

7, What are AS and F5 emissions? On 
what amateur frequencies can these emis- 
sions be transmitted? Can AS emission be 
transmitted satisfactorily using one side- 
band only? 

A, A5 and F5 both designate video 
signals; A 5 means amplitude-modulated 
video, while F5 stands for frequency- 
modulated video. 

Since video signals cover a bandwidth 
from dc up to several MHz, A 5 signals are 
seldom satisfactory if transmitted using 
one sideband only, due to phase shift of 
the low-frequency components. To over- 
come this situation, yet reduce the extreme 
bandwidth which would otherwise be re- 
quired, commercial television uses the 
"vestigial sideband" method to transmit by 
A5 signals, A vestigial-sideband signal is a 
normal DSB (with carrier) signal at very 
low frequencies, but one sideband (nor- 
mally the lower one) is cut off at 750 kHz, 
so that at modulating or sideband fre- 



110 



73 MAGAZINE 



quencies greater than 1 .25 MHz the signal 
is single sideband. Between 750 and 1250 
kHz, the lower sideband is rapidly attenu- 
ated. Thus a video bandwidth of 4,5 MHz 
is compressed into a channel only 6 MHz 
wide, including guard bands and audio 
information. 

Both A 5 and F5 emissions are legal on 
all amateur bands above 420 MHz. 

#, How does amateur TV I usually affect 
tele vision receptio n ? 

A. Alarmingly . The interference may 
manifest itself in any of a number of ways. 
Either the audio or the video parts of the 
TV signal, or both, may be affected. 

If audio is affected, the TV viewer 
usually hears a distorted version of the 
amateur's transmissions* This is usually due 
to audio rectification, the same action 
which affects hi-fi and stereo sets, BC 
radios, hearing aids, etc. 

Effects on the video may be varied. If a 
beat between the amateur's signal and the 
TV signal occurs, a cross-hatching may 
appear on the screen. If the beat frequency 
is low, this may show up as vertical bars 
across the picture. If the beat is high in 
frequency, it may be cross-hatching or 
simply a "grainy" appearance. 

In severe cases, TV reception may sim- 
ply be blotted out due to overload of the 
TV-set front end. 

Video interference due to the amateur's 
audio modulation usually shows up as 
flickering horizontal bars of dark and light. 
This is true if the amateur uses AM. With 
FM, a cross-hatching which flickers in step 
with the audio occurs. 

Cross-modulation interference may 
cause the sound of a local FM station to 
appear in place of the TV channel's sound, 
and it's possible for all these effects to 
occur at the same time (though highly 
unlikely). 

9. Describe briefly the basic sections of 
a single sideband (SSB) transmitter. In 
what section of a properly operating SSB 
transmitting system is distortion most like- 
ly to originate ? In what section is nonlin- 
earity most likely to originate? 

A, The basic sections of an SSB trans- 
mitter are the audio and sideband genera- 
tion portion, the frequency control por- 



tion, and the power amplifier. The audio 
portion restricts audio from the micro- 
phone to the frequency range necessary for 
effective communication, and the sideband 
generator translates the frequency spec- 
trum of the speech from the audio range 
into radio frequency (usually at some fixed 
frequency, to facilitate separation of the 
desired sideband). The frequency control 
portion translates the SSB output of the 
sideband generator into an SSB signal al 
the desired output frequency, and the 
power amplifier brings the signal's power 
level up to the desired point for radiation. 

Distortion most usually occurs in the 
power amplifier portion of the transmitter. 
Nonlinearity, being a specific form of 
distortion, also is most likely to occur in 
the power amplifier, but may occur at any 
point within the transmitter. Once it oc- 
curs, it cannot be removed from the signal. 

10, Define what is meant by the time 
constant in a resistance-capacitance circuit? 
How is the time constant determined? 

A. The time constant is a measure of the 
speed with which the ciruit can react to 
step-impulse stimuli, and is a function of 
the product of resistance and capacitance 
in the circuit. 

Time constant is determined by multi- 
plying the resistance in ohms times the 
capacitance in farads, with the result being 
expressed in seconds. In practice, megohms 
and microfarads are the units usually used, 
with the result still coming out in seconds. 

Time constant is sometimes defined as 
the time taken by the capacitor to reach 
63% of full charge, through the resistance, 
and sometimes as the time taken by the 
capacitor to discharge to 37% of its original 
charge through the resistance. Both these 
definitions are accurate although incom- 
plete. 

As a working rule of tliumb, an RC 
circuit will be essentially fully charged (or 
discharged, as the case may be) within 5 
time constants, although in theory full 
charge or total discharge cannot ever be 
attained. 

11. How does a squelch circuit operate? 
Draw a commonly used squelch circuit. 

A, A squelch circuit acts to silence the 
audio output of a receiver in the absence of 



APRIL 1972 



111 



an incoming signal. Most often, the circuit 
either opens or shorts out the receiver's 
audio, between detector and audio ampli- 
fier, under control of a dc level obtained 
from the carrier of an incoming signal 
(usually the avc voltage). Some circuits, 
however, make use of "between-station 
hiss** to actuate the squelch. 

Figure shows two typical squelch 

circuits, both operated from the avc line. 
When an incoming carrier causes an in- 
crease in avc level (more negative), the 
squelch circuit permits audio to pass 
through to the receiver's output. 



IN459 



l-F 
AMPLIFIER 



AF 



fo-^i- 




OUT 



AVC 



50 «F <I00K 



500K 



■ j 1/2 J2AX7 



IOK 



12, An oscilloscope is used to study the 
relationship between the input and output 
of an amplifier produced by a voice signal 
How would the scope pattern display a 
linear relationship between the input and 
output signals? 

A. If the scope is hooked up as shown in 
Fig, 9 to directly compare input and 
output signals, a linear relationship would 
be indicated by a perfectly straight line on 
the face of the CRT, Any curvature in the 
CRT display would indicate loss of lin- 
earity at that point of the signal. 







LINEAR 



NON-LINEAR 
AT PEAKS 



LOW- LEVEL 
HON-LINEARITY 



13. Draw a block diagram of an RTTY 
system showing the primary function of 
each stage. What is the proper way of 
identifying an RTTY transmission? What is 
the most widely used frequency difference 
between the mark and space frequencies in 
a conventional RTTY transmitter? 

A, See Fig. for required block 

diagram. 

An RTTY transmission should be identi- 
fied by means of CW, as well as by 
transmission of all required information in 
the international teleprinter code. 

The most widely used frequency shift is 
850 Hz with 170 Hz rapidly becoming the 
accepted standard below 30 MHz, 




KEYBOARD 



MODULATOR 

TRANSMITTER 




AUDIO 



TERMINAL 
UNIT 



DC 




RECEIVER 



73 MAGAZINE 



112 



SEE YOU AT THE WORLD'S LARGEST HAMVENTION! 



21st ANNUAL 



22 APRIL 1972 




WAMPLER'S HARA ARENA 

DEPT: S Box 44 DAYTON, OHIO 45401 

TECHNICAL SESSIONS • EXHIBITS • LADIES' PROGRAM • AWARDS 
FLEA MARKET • HIDDEN TRANSMITTER HUNT •BANQUET 



14* How can the two-tone test output 
of a linear amplifier be used to tell if a 
transmitter is working properly? Show 
scope patterns for optimum, overdriven, 
and underdriven amplifier conditions. 

A. The scope patterns produced by the 
two-tone test can be used to determine the 
audio input level at which peak flattening 
occurs in the output signal as shown in Fig. 
(in Fig. , the * optimum" condition 
is just prior to the point at which peak 
flattening begins to occur). 

Some additional information may be 
obtained from a modulation-envelope dis- 
play of the two-tone test, but it is highly 
subjective. More accurate data on trans- 
mitter working conditions is obtained from 
the "bow-tie" display. In this pattern, 
curvature of the sloping sides indicates 
nonlinearity. Flattening of the tips of the 
pattern indicates overdrive. With proper 
bias conditions, the crossover will be sharp- 
ly defined; if bias adjustments are incor- 
rect, curvature will occur near the cross- 
over point although the remainder of the 
pattern may indicate perfect linearity. 



UNDERDRIVEN 



(XXX) 



OPTIMUM 



OVERDRIVEN 





ENVELOPE 






BOW-TIE 

15. Define the alpha cut-off frequency 
of a transistor. How is this parameter of 
use in circuit design? 

APRIL 1972 



try the NEW WAY to TUNE FM 

VARACTORS and VVC'S 

to lock onto weak signals with 
AFC, and to FM or phase 
modulate crystal oscillators, 
and for remote tuning. 

write for data sheets 

EASTROIM CORP. 

25 Locust St,, Haverhill MA 01830 




NKW GLADDING 25 

FM TRANSCEIVER. 25 WATTS OUTPUT, h t h;in~ 
nets complete with xtuls tor 146,34/ 1 46.76 and 
1 46.44/ 1 46.44, Inw power position, completely 
separate Kniit-ree xtal switching. (Amateur net 
$244.95) OUR LOW INTRODUCTORY PRICE 
<2f2.5(h With matching AC supply (reg. S2«*9^S) 
S25S.OO, Write for literature. Ham Ms S9M.00. 

AMATLUR WHOLt-SALI Fl I CTRON1CS 
8SI7S.VV. 129 Terrace Miami, FL 33156 305-233-363 



VHF CONVERTERS 

We manufacture a complete line of converters for 
50 through 432 MHz. Models to suit all needs DX, 
FM, ATV, MARS, etc. A postcard will bring our 
new FREE CATALOG with pictures, schematics, 
specifications and prices. 

JANEL P.O. Box n2 

LABORATORIES 



Succasunna, N. J. 07376 
TEL: 201 584 6521 



V i brople X 

ENJOY EASY. 

&MV RESTFUL KEYING 

$22.95 to $47.95 

THE VIBROPLEX 

CO.. INC. 

833 Broadway. 
New York, NY 10003 

WORLD QSL BUREAU 

5200 Panama Ave., Richmond CA USA 94804 
THE ONLY QSL BUREAU to handle all of 
your GSLs to anywhere; next door, the next 
state, the next county, the whole world. Just 
bundle them up (please arrange alphabetically) 
and send them to us with payment of 54 each. 







TONE CONTROL DEVICES 

Decoders, Encoders, Logic Processors, Autopatch, COR 
Compact, solid-state, plug in modules. Reasonably 
priced. Wnte for free Application Notes & Catalog 

DIGITONE BOX 73 BELLBR00K, OH 45305 



113 



CORNEL 



tube 



<dS^Send For *& 

CORNELL'S ' 
New Color , 

. 48l*ffi, New iterm IN LOTS OF 100 IN 24 HOURS! 

4215 S University Ave. San Diego, Calif. 92105 



tuhft ORDER FREE 

IF NOT SHIPPED 

IN LOTS OF 100 in 24 hours! 



WE PAY HIGHEST CASH PRICE 

for Electron Tubes & Semiconductors 

Immediate Payment on Unused Tubes 

H & L ASSOCIATES 

Elizabethporf Industrial Park 

Elizabeth, New Jersey 07206 

(201) 351^200 



ELECTRONICS 1 LATEST 

TROUBLE-SHOOTER 



Model EC 
Patented 



A compact— complete 
circuit analyzer 

The SERVISET 




INTRODUCTORY 
PRICE 

POSTPAID 



A precision engineered professional Quality electronic 
test instrument Idtal for field or bench servicing of 
ell types of Communication i qea r 
CHECKS: sync, sweep, video, audio circuitH. 
hitfh voltaKe supplies (DC, RF or Ful*e), low 
voltage supplies, coils, capacitors, resistors 
tubes, transistors, diodes, transformers* speak* 
ers, etc. Will locate trouble to a pailicuiar 
stage, determine defective component and can 
actually be clamped in circuit to restore cir- 
cuit operation temporarily in 80^ of component 
or tube defects. Ideal for locating and confirm- 
ing intermittent*, 

SPECIFICATIONS: 
RF it AF Signal Tracer, RF I AF Signal Injector, AC 
ft DC Voltage Indicator 0/eO '550/20,000 DC Polarity 
Indicator eO 550 '20,000 volt*, Lo ohms 0-5, Hi ohms 
O-SGOk-20 megohms, Tests Condensers, .00025-12 mfd . 
Tests Reststors 2 ohms-20 meqohms. 2 Capacitance 
Sub ranges Oil A 4-40 mfd.. 3 Resistance Sub ranges 
50-500 ohms 5b-25k, I00k-l meg. 

30 Day Money-Back Guarantee 

•*3r"3\LEE ELECTRONIC LABS,, INC. 

{^ECtZ/ 88 Evans Street 

Watertown, Massachusetts 02172 



TS-382 AUDIO OSCILLATOR 

Frequency range 20 to 
200,000 CPS in four bands, 
output imp. 1 000 ohms ( amp 
liiudes continuous variable 
0-10 volts; FreQ. response 20 
CPS to 150,000 CPS; aporo*. 
±1 DB; Freq, accuracy ±6%, 
stability ±2%; Hum 60 DB be 
low rated output; attenuator 
accuracy 3% except 10 Micro. 
V +2 or — 3 Microvolts, Power 
input 115 V, 50-1600 eye. 
Output 100 MW. With rune 
tubes, calibrated tuning iial, 
freq. range switch, output level com. output level attenuator, 
signal input and output jack, output level meter, vibrating 
reed -type meter used as accuracy check of the osc. calibration. 
Size: 18 3/4 x 10 * 12-3/4". Shpg, Wt.: 75 lbs 

Prices: Used, serviceable: $75, Checked: $85. 

All Prices are F.O.B., Lima, Ohio 

Address Dept. 73 

Send Now For Our BIG CATALOG '72 



FAIR RADIO SALES 

1016 E. EUREKA • Box 1105 - LIMA, OHIO • 4500? 




T4 



A. The alpha cut-off frequency is that 
frequency at which "alpha" (common-base 
current gain) of the transistor drops to 7 I 
(3 dB down) of its value at "low fre- 
quency" (normally 1 kHz). In other words, 
it is a measure of the high-frequency 
performance of the transistor. 

Alpha cut-off frequency has little appl- 
ication to current circuit design, because 
the common-emitter circuit is more com- 
monly used. It is, however, usually higher 
than the corresponding cut-off frequency 
for common-emitter circuits, and indicates 
the maximum frequency at which the 
transistor may be useful in amplifier, oscil- 
lator, and switching circuits. Normally, a 
transistor will oscillate readily at its alpha 
cut-off frequency, but may not function 
properly as an amplifier at this frequency. 

16. What are inductive and capacitive 
reactance? How are their phase angles 
related? How does their reactance affect 
actual power dissipation in a circuit? 

A, Reactance is a measure of the opposi- 
tion to flow of alternating current. Induc- 
tive reactance is a measure of the opposi- 
tion offered ac by an inductor, while 
capacitive reactance measures the opposi- 
tion offered by a capacitance. Unlike resis- 
tance, reactance dissipates no power, but 
merely shifts the phase of current with 
respect to voltage, thus making a part of 
the power unavailable for dissipation. 

Pure reactance of either type shifts 
phase by 90 degrees. With inductive react- 
ance, the current lags the voltage by 90 
degrees, and with capacitive reactance, the 
voltage lags 90 degrees behind the current. 
In a circuit containing both reactance 
and resistance, only the resistance dissi- 
pates power* The power dissipation is 
reduced by presence of the reactance, 
because it makes a portion of the available 
power unavailable to the resistance- 
Inductive reactance increases with fre- 
quency, while capactive reactance de- 
creases with frequency. Thus at dc ? an 
inductor is a short circuit while a capacitor 
is an open circuit, and at "infinite" fre- 
quency, the roles are reversed. 

17. How does the positioning of a 
powdered iron tuning slug affect the fre- 
quency of the oscillator it is tuning? 

73 MAGAZINE 



A. Since the powdered iron slug has 
higher permeability than does air, as the 
slug moves into the coil it increases the 
inductance and thus lowers the frequency 
of the oscillator 

Brass has lower permeability than air, 
and is sometimes used for tuning slugs. 
When a brass slug is used, inductance 
decreases and frequency rises as the slug is 
inserted into the coil, 

18. Define the deviation ratio in a 
frequency modulated signal 

A« Deviation or * "swing" is the differ- 
ence between the apparent instantaneous 
frequency of the modulated-signal enve- 
lope and that of the carrier. Deviation ratio 
is the ratio between deviation and the 
frequency of the modulating signal. Strict- 
ly speaking, it is the ratio between maxi- 
mum deviation, and the maximum modula- 
ting frequency. In an amateur NBFM signal 
below 52.5 MHz, with maximum modula- 
ting frequency of 3 kHz, deviation ratio is 
not legally permitted to exceed 1.0. 

19. What type of signal will be produced 
when the output of a reactance modulator 
is coupled to a Hartley oscillator and 
multiplied in frequency? 

A, FM. 

20. How would the reception of a single 
sideband signal be affected if the carrier is 
not completely suppressed? How can spur- 
ious signals in the output of the mixer 
stage of an SSB transmitter be suppressed? 

A. The incompletely suppressed carrier 
may produce a beat frequency with the 
receiver's bfo if tuning is not exact. This 
beat appears as a low-pitched "growl/' and 
may vary slightly in frequency as propaga- 
tion effects shift the frequency of the 
in coming signal, or the bfo shifts slightly. 
In addition, the carrier may cause interfer- 
ence to other signals. 

Spurious signals in the output of the 
mixer stage can be suppressed by proper 
design, by choosing input frequencies so 
that no mixer products except the desired 
one fall within the range of the output 
tuning circuits, and by the use of many 
selective tuned circuits between mixer and 
antenna. High-level mixers are to be avoid- 
ed in the interest of suppression of spur- 
ious signals. . . , Staff 
(to be continued in the May issue of 73} 

APRIL 1972 



SPACE-AGE TV CAMERA KITS & PLANS 

BE A PIONEER \H HOME TELECASTING 1 Build y*, *»., 
TV CAMERA. Ivbdel XT-TA, Sw,« 0, 1116.95 pp. Snl-d- 
Stair, Siep'ty'itep ctmrrutiicn myiuol- Hi jn quoUv 
Comets to my TV *ii4iou? wod^.eaiiov Idwf lor ham, 
■tpmuauNtfi, education, mdkn»ry, rtt 

PHONE or WRIT! for CATALOG. 

Mttiy 0#w (tin. pom and plant available include (toner 

L_.~ L^.-*. /J-if __:l. ...J- ^ I . ■ * 



- r ■ r - — f 

1201 n, Broadway ATV Research Dakota cur neir. 6B7j» 




2 and 6 Meter 
F.M. used G.E. — Motorola 

REA etc. 

For info send self addressed 
stamped envelope to — 

F.M. HAM SALES 

P.O. Box 1574, Ft. Worth, TX 76100 



FREE CATALOG 



HARO-TO-FIND PRECISION TOOLS 

Lists more than 1700 Items — pliers, 
tweezers, wire strippers, vacuum systems, 
relay tools, optical equipment, tool kits 
and cases. Also Includes four pages of 
useful "Tool Tips" to aid in tool selection. 



tTEJNTSEirsr TOOLS txnA a: 

4117 N. 44th Street, Pkoerui, Aniom 8»I8 



TELETYPE -RIBBONS -TOROIDS 

Lowest prices anywhere ! 

88 mhy TOROIDS 40/510. ppd. - 

Fresh RTTY Ribbons 12/S3.50 ppd, 
MACHINES - GEARS - SUPPLIES - TAPE 

Stamp for If A II U/OHI T 302X PASSAIC AVE: 
CATALOG ¥HH l¥£ULi STIRLING, N.J. 07980 




ARC FM9 (R-508} RECEIVER 1 18^ 143 MHZ 
TUNABLE. 9 TUBE SUPERHETERODYNE AM 
RECEIVER, IF 15 MHZ CHECKED OUT WITH 

SCHEMATIC $14,95 

BLOWER 115VAC60CPS 1PK20CFM 

3400 RPM $4.95 

TELETYPE TAPE 3/8 canary 

mwm „ 10 rolls SI 25 

NEW CA TALOCUE now A VAILABLE 104 

FRANK ELECTRONICS 

407 Ritter Road Harrisburg, PA 1 71 09 





NU SIGMA ALPHA 

International Amateur Radio 
Fraternity. Memberships now 
available, Includes wall certifi- 
cate, LD. card, newsletter, and 
more. Send for free brochure. 
BOX 310, DEPT.73, 
BOSTON MA 02021 



2 METER PREAMP 

More Gain, Less Noise For The Money! 

20 db gain 

Noise Figure 2.5 

12 VDC Operation 

Small Size: VA x 2% x % Only . . $12.50 
Kit $9.50 

Option For 150-250 VDC Operation -$1 

DATA ENGINEERING INC. 

Box 1245 "Springfield, Va. 22151 

115 




BRAND NEW FREQ-SHlFT TTY MONITOR: 
NAVY OCT-3; FM Receiver lype, freq. range 1 lo 26 MHz 
in 4 bands, cont. tuning. Crystal calib. Reads up to 1500 Hr 
deviation on built-in VTVM. Cost SI 100.00 each! In 
original box, with instruct, book & cord, fob Mariposa. Cal, 
Shpg wt 110 ibs.< »•'-•<»»- + .**.**...»,»..»,,*. 49.50 



HIGH-SENSITIVITY WIDE BAND RECEIVER 

COMMUNICATIONS •BUG DETECTION 
• SPECTRUM STUDIES 
38-1 000 MHZ AN/ALR-5: Consists of brand new tuner/ 
converter CV-253/ALR in original factory pack and an eac* 
used, checked OK & grid main receiver R-444 modified for 
120 v. 50/60 hz. The tuner covers the range in 4 bands; 
each band has its own Type N Ant, input. Packed with each 
tuner is the factory inspector's checkout sheet. The one we 
opened showed SENSITIVITY: 1,1 uv at 38.4 mhz, 0.9 at 
133 mhz, 5 at 538 mhz, 4'/a at 778 mhz, 7 at t ghz. The 
receiver is actually a 30 mhz IF ampl, with all that follows, 
including a diode meter for relative signal strengths: an 
at ten. calibrated in 6 db steps to —74 db, followed by an 
AVC position: Pan,, Video & AF outputs; switch select pass 
of ±200 kh* or ±2 mhz: and SELECT AM or FM! vVuh 
Handbook & pwr input plug, all only . 375.00 



We have SP-600-JX, R390, WRR-2 Receivers. Ask! 



REGUL PWR SPLY FOR COMMAND, LM, ETC. 

PP-106/U! Metered. Knob-adju stable 90-270 v up to 80 ma 
dc: also select an AC of 6.3 v 5 A* or 12*6 v 2Vi A or 28 v 
2Vfc A. With mating output plug & all tech, cata. Shpg. wl 

BARGAINS WHICH THE ABOVE WILL POWER: 

LNM») Freq. Meter: 125—20 MHz, .01%, CW or AM, with 
serial-matched caiib. book, tech. data, mating plug* Shipping 

W l - lO J Qi f * • < ■• ( r t * # ■ '■ *' 4 ■ <■•<>>■•■< i > i t .... . t}f .bU 

TS-323 Freq. Meter: 20— 480 mhz, 001% 169.50 

R23A/ARC5 Command Q-5'er 190-550 KHz t exc. cond 16.95 
A.R.C.R22 Command rcvr 540-1600 KHz, exc. cond . 17.95 
A.R.C. R15(MIL R-&09)Command, 108—135 MHz,new27.50 



47! 



NEMS CLARKE ^1670 FM Rcvr 55-260 MHz 

like new p 

WWV Rcvr/Comparator 2 ^i - 20 MHz, solid state . 
Empire Devices NF 114 RFI meter is a red-hot reeeut-i 
from 150 KHz to 80 MHz ...,__... 295.00 



:88 



^— 



Attention! 

Buyers, Engineers, advanced Technicians: 

We have the best test-equipment & oscilloscope 
inventory in the country so ask for your 
needs, , , don't ask for an overall catalog , , t 
we also buy * so tell us what you have. 



R. E. G00DHEART CO., Inc. 
Box 1220 GC, Beverly Hills, Calif. 90213 
Phones: Area Code 213, Office 272-5707 



NEW GLADDING 25 

FM TRANSCEIVER, 25 WATTS OUTPUT, 6 chan- 
nels complete with xtals for 1 4h.34/ 1 46.76 and 
146,94/146.94, low power position, completely 
separate xmit-rec xtal switching. < Amateur net 
$249.95) OUR LOW INTRODUCTORY PRICE 
$212.50. With matching AC supplv (re>:. $299.95) 
S25S.OO. Wrile for literature. Ham-NTs $99v00. 

AM ATI-: UR-WHOLESALK ELECTRONICS 

8817 5.W. \ ;»9 Terrace Miami, FL 33156 305-233-363 



HHL 



DEVICES 



HAL ID-1 REPEATER 

IDENTIFIER 

$75 

Circuit board wired *& tested* 

TTL logic. Power line frequency counter for 3 minute 
or less liming and control. Easily reprogrammable 
diode BOM uses only 27 diodes (depending on call) ro 
send DE "any call". Low impedance audio with 
volume and tone control. All circuitry including PS on 
small G10 glass PC board. Write for full details. HAL 
DEVICES, BOX 365. URBANA, ILLINOIS 6180I 







you/ 

asked/. 

FOR 




HERE IT IS! . . . one complete U.S. Callbook 
and one complete DX Callbook per year and no 
change in price. In addition you can keep your CALL- 
BOOKS up-to-date through a subscription to the new 
Service Edition Series published each March 1, 
June 1 and September 1 — each one covering new 
licenses and all activity during the preceding quar- 
ter. Annual subscription to complete Winter CALL- 
BOOKS plus 3 Service Editions only $14.95 postpaid 
lor the U.S. and $11,45 postpaid for the DX. 



Over 285,000 QTHs 
in the U.S. edition 




w 






^liMI <M*« 



Over 180,000 QTHs 
in the DX edition 



.-. 






*6 




These valuable EXTRA features included in both editions! 
• QSL Managers Around • Prefixes by Countries! 



the World! 

Census of Radio 
Amateurs throughout 
the world! 

Radio Amateurs' License 
Class! 

World Prefix Map! 

International Radio 

Amateur Prefixes 



• Zips ou all QTHs! 

• A.R.R.L Phonetic 
Alphabet! 

• Where To Buy! 

• Great Circle Bearings! 

• International Postal 
Information! 

• Plus much more! 



See your favorite dealer or order direct {add 25$ for 
mailing in U.S., Possessions & Canada. Elsewhere add 
50$), 

50 YEARS OF SERVICE 
TO RADIO AMATEURS 

GET YOUR NEW ISSUE NOW! 



writs fOR 
fftn 

BROCHURE 



RADIO AMATEUR 

ca 



lit. 



oo 



Kin 



Deot 6 925 Sherwood Orive 
Lake Bluff. III. 60044 



■■ 



Wm . B nice C 'amen m WA 4 UZM 
324 S. RiverhMk Drive 
Temple Terrace FL 3361 7 



The Poorer But Wiser 
Hams FM Base Station 



By this time FM is clearly here to stay 
and the confirmed FM addict wants at 
least a mobile and a base station, if not a 
walkie-talkie as well. The older, tube-type, 
commercial sets, although obsolete for their 
original intended purpose, offer the ham 
excellent sensitivity, power, and stability, 
and unless they are positively ancient, they 
offer a narrow passband as well. The latter is 
advantageous when you are digging for weak 
stations, assuming they are on frequency. 

Since most of the commercial gear was 
mobile (there being as many as fifty mobile 
units for a single base station in some 
installations) it follows that an obsolete 
mobile unit is the cheapest and most avail- 
able rig today. While much of this is hard to 
modernize into useable mobile material, all 
of it is easy to rebuild into base stations. 

Now, as in other branches of the ham art, 
you will have to do a little extra work if you 
want to save extra money. For instance, as 
with the old recipe for bear steak that starts 
"first catch a bear/' you must first find an 
old radio. This is easier to do than you might 
think just from reading the magazine ads, 
because the prices which the General Elec- 
tric Pre-Progs, Motorola 80 D\ and similar 
rigs bring do not justify advertising them. 
However, find a firm that advertises more 
recent gear, write them or drop in at their 
warehouse and you will usually find the 
older, cheaper gear there and sometimes 
almost for the asking. Another good method 
is to have a friend inquire over the air, or 
check the goodie-row offerings at your 
nearest hamfest. At one last month, 1 bought 
a good Link 1905 receiver for $1. With 
$1,60 for two crystals from JAN and odd 
parts from my well-stocked junk box, it is 
now a serviceable 76—94 monitor receiver 
sitting in my bedroom. This is admittedly a 
better than average bargain, but. you will be 



astonished at how much radio you can buy 
for how little if you go back about two 
model styles, I have bought working sets for 
$40 and you-fix-its for $5. See page 50, 
July, 71 , issue of 73 for a representative list 
of dealers, or leaf through any current copy 
for others. If they advertise current type- 
accepted commercial FM gear, they probab- 
ly have the less expensive earlier stuff, also. 

There is no problem at all in getting 
circuit information and specifications for 
ordering crystals if you use either General 
Electric or Motorola gear, as there are books 
of prints advertised in the ham magazines 
nearly every issue- If you play with Link, 
RCA, Bendix, and some of the others, you 
may have to canvass the local ham fraternity 
for circuit data, but most hams will cheer- 
fully let you Xerox any prints or instruction 
books they have, so do not fear the other 
makes, just prepare to do your homework if 
you use them. 

Possibly the best buy is the GE Pre-Prog- 
ress line (ES 12, etc.). These were six-volt 
units to begin with, although some were 
modernized in various ways to 12. Later 
models came in original 12 volt condition, 
but this is not really an advantage when you 
decide to convert to 1 10 ac, and you might 
save money as well as work by buying a 
six-volt model. 

The advantage, other than cost, of the 
six-volt models is that the filaments are all in 
parallel. Whereas the original tube line-up 
employed low current tubes wherever pos- 
sible (6BH6, 6BJ6, etc.) if you have a 
parallel filament circuit, you can substitute 
other tubes for increased gain, or just be- 
cause they are more available. In the 12 volt 
versions, you must be sure the filament 
currents match properly on each side of the 
string or some tubes will be starved while 
others are over-fed. In addition to risking 
early tube burnout, such discrepancies can 



APRIL 1972 



117 



do strange things to stage gain which will be 
hard to find. 

The first thing to do is separate out the 
leads which must be fed low voltage dc, such 
as the relays, and those which can use ac, 
such as the filaments, A choice is available in 
supplying the high voltage, as follows: You 
can pull the vibrator out, feed low voltage ac 
to the old vibrator transformer primaries, 
and diode-rectify the secondaries. However, 
you will recall that the vibrator transformers 
expected 120 Hz ac from the vibrators, and 
used a divided primary. If you run 6 volts ac 
to half the primary, you will come up with 
about the right secondary voltage, but the 
transformer may become too warm. This 
varies from model to model and from make 
to make. The Link 1905-1906 series had 
husky transformers that run barely warm 
this way, but the GE rigs were engineered 
fairly close and run warm, while some other 
makes will actually burn up. However, if you 
have the ac in sufficient quantity to feed 
them (6 volts at up to 30 amps!) you can 
easily try this method and see whether the 
vibrator transformers will handle it- If they 
do, you are home free, or almost so. You 
still must supply dc to the relays, and the 
easiest way is to use a bridge rectifier across 
a filament winding, if it is not grounded, A 
separate low-current filament transformer 
may be required. With such a bridge recti- 
fier, you may need no filtering. If you use a 
half wave across the regular grounded fila- 
ment winding, you will need beaucoup 
capacity to keep the relay from chattering, 
but either method works. 

There is a power limitation in using the 
old vibrator transformers as described. The 
GE Pre-Progs, for example, used two trans- 
formers, one for low voltage and the other 
only for plate voltage for the 2E26 final. 
The rig was planned for 7 — 10 watts output 
and that is about all that little transformer 
can produce. It does not help much to 
bridge it, because the increased current 
drawn will drop the voltage so that you are 
back about where you started, However, this 
rig can readily be "high-powered"* if you 
build a new high voltage supply operating 
directly from the ac mains. To do this most 
easily, you pull out the old vibrator sockets 
and their transformers, leaving the electro- 



lytic cans, as they will serve in the new 
supply. Either on the chassis, if you pick the 
right size, or somewhere else, you mount a 
TV transformer and bridge rectify it for the 
final plate supply, using the center tap for 
the general low voltage supply for the rest of 
the rig, FM transmitters do not require 
nearly as good filtering as do AM or side- 
band gear, so you need only add a new SjuF 
1,000 volt oil filled paper capacitor for the 
final plate supply. 

Since you will be using about double the 
old plate voltage, you might as well substi- 
tute a 6146 for the 2E26 and get the added 
wallop it can produce. Some Motorolas used 
two 2E26 J s and you can plug in two 6146*s 
in place of them directly. If you try this on 
the GE ESI 6, you will find that the sockets 
are too close together. Take heart. Simply 
remove the metal shields from the bottom of 
the tubes (carefully!) and then file a flat side 
on each tube base where they would other- 
wise touch. (One tube will be for the right 
hand side and the other for the left hand 
side, not interchangeable.) 

On any such gear, inspect the high voltage 
bypass capacitors closely, because most of 
them will not stand doubling the ratings, as 
we are now doing. Be sure also that any 
dropping networks deriving voltage from the 
final high voltage supply are correctly re- 
engineered, On most sets, this latter is 
unnecessary as the manufacturers did not 
want to waste any more power than they 
had to waste, and so the high voltage supply 
(vibrator or dyna motor) delivered only its 
full output to one terminal. 

This may sound like a lot of work, but 
actually it should take only a few evenings, 
even if you have never done it before. The 
result will be a high quality signal at good 
power and minimum cost. With crystals, the 
new power supply components, and the 
usual number of tubes and other repair 
parts, it should never exceed $75, but don't 
judge it only by the present cost. Remem- 
ber, this old mobile junk originally cost 
upwards of $1,000! 

One of the happiest accidents about the 
Pre-Prog receivers is that while they were 
originally designed for wide-band reception, 
the loading on the i-f coils is such that if you 
merely peak every coil precisely on frequen- 



118 



73 MAGAZINE 



cy ("Christmas tree them") you will achieve 
a pass band about 15 kHz overall which is 
highly compatible with modern narrow-band 
equipment. The overall gain, of course, 
improves in this process and the receivers are 
quite satisfactory without additional pre- 
amplification, although putting a good tran- 
sistor preamp ahead of them makes them as 
hot as you could possibly want. Originally 
rated at .6juV for 20 dB of quieting, when 
the i-f strip was stagger-tuned to 120 kHz 
wide band service, returning brings most of 
them to .5 or better, and a pre-amp drops 
them to ,2 ox .3, The squelch action is 
uniformly good. 

One additional modification which I 
heartily recommend, but which is certainly 
optional, is junking the typical carbon mike 
in favor of a reluctance, ceramic, or other 
better-sounding type. If you rework a Pre- 
Prog in this way, you can get an added 
advantage of a well compressed audio signal 
as well. Remove the mike transformer and 
you will find that the hole in the chassis 
exactly fits a 9 pin socket. Wire a two-stage 
triode amplifier here, using a I2AT7 or 
equivalent, and feed the resulting signal to 
the existing audio tube, just as if it were 
coming from the secondary of the mike 
transformer. The easiest way to do this is 
with a 9 pin Vector socket, so the two entire 
stages can be built externally and then just 
set in place. It does require a special shield 
that mounts on top of the chassis, but I 
always use a 35mm film can instead, because 
they are more available (punch holes in it for 
ventilation!). 

This will now drive the modulator tube 
into compression, and when you set the 
deviation control to the proper point, you 
will have a high-average, or loud-sounding, 
though narrow, signal. The gain required of 
the first stage depends on the mike, so try a 
12AX7 and a 12AU7 in the socket before 
you quit, and select the one that gets you 
the best on-the-air reports. , . .WA4UZM 



FREE ALARM CATA 



64 PAGEf Flt-LED WITH 3»0 BURGLAR J 
AND FIRE ALARM PRODUCTS FOR 
INSTALLERS AND ELECTRONIC 
TECHNICIANS. INCLUDES RAOAR, 
INFRARED, CONTROLS, HARD-TO- 
FIN O PARTS. AND 6 PAGES OF 
APPLICATION NOTES. 





/<■ mountain west alarm 
^4# 4215 n. 16th sL, phoenix, az. 



85016 



m 



FM Schematic Digest 

A COLLECTION OF 

MOTOROLA SCHEMATICS 
Alignment, Crystal, and Technical Notes 

covering 1947-1960 

136 pages 1 r/2" x 17" ppd $6.50 

S.Wolf 

Box 535 

Lexington, MA 02173 



^ ^^ ^^^^^ ^ 



AUDIO CW FILTER 

Active fitter witti 750 Hz center frequency and band pass of 200 Hz 

Deluxe model with cabinet , „» 4 ,„„„.„~320.00 

Basic, without cabinet... ,„„„**,.•».*„.<;».*,»< ...„„.,. $16.00 

POWER SUPPLIES 

12 volts @ 5 amps. I.C. regulated to 1% of output and short circuit 
protected. 

PS 125 „ ,.,. „„.„*„, „„ T .$40,00 

Custom supplies to your specifications. Write for quote. 

ORP TRANSMITTER 

80 or 40 meter transistor transmitter. Complete \y wired and tested. 
Operate from 6 18 VOC, but best on 12 VDC. Great for low power 
C.W Cabinet not supplied 

CjA'I (buU rniAi input) ,-,»«,*#»*••* ...,«.>„<.««. _**„„,«.,*,. ,+n^.io.UU 

2 METER FM POWER AMPLIFIER* 

5-10 watts input gives 15 to 35 output @ 13.5 VDC automatic trans- 

mit-receive relay Unit will operate on H-15 VDC. 

FM-I.... ,m «.. *■■■ $65.00 

Terms: Send check or money order. Add $1.00 for postage 

and handling. Allow one week for shipment after 

receipt of order, 

Dimi 1879 PRINCETON DRIVE 

11,11 SYSTEMS CLEARWATER. FLORIDA 3351 5 



1 ^ ^ s 




DOIT 

YOURSELF 
RESISTORS 
FLEXTRIM® 



Resistance wirekit — ,01 to 300 ohms per foot 
wire — 7 different resistance wires — 1 1 bob- 
bins to fit PC board — for precision low value 
resistors only $12.95 postpaid? 

TECHNICAL DATA 

19025 Parthenia/Northridge CA 91324 



LEARN RADIO 




Album contains three 12" 
LP's Vh hr. Instruction. 



THE EASY WAV! 

• No Books To Read 

• No Visual Gimmicks To 
Distract You 

• Just Listen And Learn 

Based on modern psychological 
techniques—This course will take 
you beyond 13 w.p.m. in 
LESS THAN HALF THE TIME! 
Available on magnetic - tape, 
S9.95 - Cassette, S1 0.95 



EpSllON \§\ RECORDS 



508 East Washington St., Areola, Illinois 61910 



APRIL 1972 



119 



REGULATED POWER SUPPLY FOR NIXIE READOUT STAGES 

5 Mv ripple at maximum rating 
110 volt input with output of 170 volt 15Ma • 5 volt 600 Ma regulated to ,5% 

SHORT CIRCUIT PROOF 
Made especially for Nixie Readout Clocks, Frequency Counters using NX101 stages: 

$14.95 



NIXIE 



STAGE 



4 i 



NEW TTL LOGIC" 



AT 



LOW 



LOW 



PRICE 



READ OUT STAGE 
SPECIFICATIONS 



ichcdult btlo* 



KITS ARE PURCHASED 
AS LISTED 



BASIC KIT NX 100 

NL 9405 ntxi* rmad out tub* 

NL 9405 tub* iock*r 

7490 Dacod* 

7441 Da cod* r driver 

Rviiitor 

trtctwd and DrilUd glan •pony PX. board 



NX10O-Q SAME AS NX 100 
WITH ADDITIONAL QUADLATCH 



DELUX KIT NX101 

NL 94DS note rtid out lub* 

NL 940S tube socket 

7490 Decide 

7441 Decoder/driver 

Reai&tor 

Etched & Drill-ad gins epOfcy PC. boird 

7475 Quid Letch 

2 ■ 16 Pin I C socket mtmbly 

1 14 Pin socket iHBinblv 

10 pm PC baird socket 



PLEASE ORDER BY 
KIT NUMBER 



quantify mm 



mino-ir 



NX101 



13 


$14.45 


$16.7$ 


$1895 


4-9 


12.95 


15,25 


16,95 


10 - up 


1249 


14J5 


16.45 



NX 101 

NIXIE 

READ OUT 

STAGE 

TTL LOGIC 



ALL BOARDS 
DIVIDE BY 10 



DIVIDE BY 6 



-WITH CUAD LATCH 
Completely guarantied 



R & R ELECTRONICS 

311 EAST SOUTH ST. 
Indianapolis, Ind. 46225 



• NL 940s fieaa Out Tube 
with two decimal points 
supplied, {at equivalent). 

• 2 i 3 etched and drilled 
glass epoiy printed circuit 
board. 

• Accepts 10 pin PC board 
connector 

• Voltage requirements 5 y&lts 
DC 80 ma for integrated 
circuits, 170 to 300 volts 
DC at 2 ma for the read 
out tube. 

• 3TTL INTEGRATED CIRCUITS 

• 7490 Decade suppli*- ICO 
code output 

• 7475 QuidJatch *. -e$ the 
count while the decade is 
re-counting not used in 
digital clocks (when quad 
latch is not used jumpers 
are required). 

• 7441 Decoder Driver converts 
the BCD code to ten different 

signals reeded to drive the 
read out tube, 

BY INTERCHANGING 
OF 3 JUMPERS THE 
P,C. BOARD IS 
ADAPTABLE TO 
DIVIDE BY 6 OR 
DIVIDE BY 10. 



120 



73 MAGAZINE 



INTEGRATED CIRCUITS 

FACTORY FRESH — NO REJECTS 
W/SPEC. SHEETS 

FAIRCHILO — PHILCO — RCA 
MOTOROLA — NATIONAL 

NEW LOW PRICES 
RTL or TTL LOGIC 

UL 900 Buffer 80tf 10/530 

UL 914 Gate 80tf 10/5.50 

UL 923 JK Flip-flop $1.50 10/8.50 

MC 790P Dual JK Flip-flop $2,00 10/18.95 

MC 890P Dual JK Rip-flop $2.00 10/18.95 

♦ ♦ ♦ 

MC 767P Quad Latch 3.00 

MC 9760P Decade ._» ,„ 5.00 

ONE EACH OF 3 ABOVE $10.50 

♦ '.♦.'"■# 

7400 Quad 2 Input NAND Gate 65 <t 10/5.95 

7404 Hex Inverter 65^ 10/5.95 

7441 A Decimal Decoder/Driver 

$3.50 10/29.95 

NEW1I 7447 7 Segment Decoder/Driver 

$3.10 each 10/27.95 

7473 Dual JK Rip-flop $1.30 10/10.95 

7475 Quad Latch ._ „_ $2.10 10/19.95 

7490 Decade Counter $2.40 10/19.95 

709' Op Amp „....„,...„„.„„„. ™„$1.75 10/16,50 

741 Op Amp »^_ $2.70 10/25.00 

CA 3035 Linear Amplifier $2.25 10/21*95 

LM 30 9 K 5 V Regulator $3.75 10/$34.95 

14 Pin Dual Inline socket terminals 

251 10/2.25 

16 Pin Dual Inline socket terminals 

304 10/2.75 

♦ *# • 

NEW NATIONAL Long Life Nixie tubes NL 
940$ 0-9 wtth two decimal points 

$4.50 ea. 10/42.95 

SOCKET for NL 940S _. - MQ4 each 

100 KC CRYSTAL NEW .-.^^ T .„„ , .„ ,„„„„.. — $3.95 

» # ♦ 

88 MH TOROIDS 10/3.00 

♦ ♦ ♦ 

REGULATED POWER SUPPLY 
FOR NIXIE READOUT STAGES 

5 Mv ripple at maximum rating 

110 volt input with output of 170 volt 15Ma 

5 volt 600 Ma regulated to .5% 

SHORT CIRCUIT PROOF 

Made especially for Nixie Readout Clocks. 
Frequency Counters using NX 101 stages: 

Kit: $14.95 

♦ ♦ ♦ 

Miniature reed switch glass enclosure %" 
long, ,««_«—«„— «»35# ea. 10/3.00 

r^21 R & R ELECTRONICS 
■ B] 311 EAST SOUTH ST. 
J™?J INDIANAPOLIS, 1ND. 



$5.00 minimum order 
Reese add sufficient postage. 



COOLING FAN BLOWER 4 pole 110V 60 eye 
motor with 4 b laded nylon fan. Very qu.et* 
about 50 CFM 2V4"W x 3"H x 2tf"D. Sti. 
wt- 3 lbs. .„, ^ _ $2.25 each 



PRECISION RESISTORS Pack of 100 $1.98 
1000 PIV DIODES 1 Amp Epoxy 10/$2.95 



ARN-30 108-135 mc tunable receivers. High 
frequency version of the famous com- 
mand receivers. Listen to local airport 
frequency or convert to 2 meters. Like 
New with schematic and operating in- 
structions. 12 lbs, _ m _JM-95 



Western Union facsimile machines, send 
and receive pictures and memos. Works 
on 115 v 60 cycles. Shipped with auto- 
start, auto-phase pos-to-pos, conversion 



instructions. 20 lbs. 



....*.. ....... 



$19.95 






Telfax paper for above facsimile. 

2e each 1000 for $12.95 



Teletype model 14 printer pulled from serv- 
ice from Western Union. Units are in 
good condition. 75 lb. shipping weight. 
While they last ■...;.■■—■ .^ $29.95 ea. 



RADIO RECEIVERS R-257/U 

BACK WITH AN EVEN BETTER SUPPLY 

R & R has the Motorola Plug !n*s we sold 
out of last year and more. 

We now have the popular LOW BAND 25-50 
MC equipment* Unit comes with these 
plug- ins: 

. 1st IF & 2nd Mixer 

# RF * 1st Mixer 

• Oscillator-Doubler unit-Amplifier 

• 2nd IF & Discriminator 

# Audio Squelch 
« Filter Unit 

SCHEMATIC Diagrams for all units supplied 



COMPLETE SET 



^fc*HA*Mi 



$9.95 




APRIL 1972 



121 



LIC 



GUID 



Try Any of These Modern, Comprehensive License Books on 10-Day FREE Trial! 



(OflCTGLflSS UC9BI 
STUDY on 



NOVICE-CLASS 
LICENSE STUDY GUIDE 

Getting a Novice license 15 
just about as easy as 
falling off a log— with this 
new study guide. All the 
mystery and confusion is 
taken out of learning the 
theory involved in the FCC 
exam. It is simple and 
logical, faking the basics 
of electricity and radio and 
exposing them as the 
really simple things they 
are, This book was written by an average 
ham to be read by absolute beginners. It Is 
not for engineers, nor for children, but for 
the reader with the equivalent of a high 
school education and the interest to think 
thfngs through. The theory is simple, and 
there is no reason why anyone cannot get an 
amateur Novice license after a tew days 
study, 160 pps, 
Order No. 572 16.95 hardbound f %2.9S paper 

ADVANCED-CLASS 
LICENSE STUDY GUIDE 

Tells all you need to know, 
with complete, thorough 
answers to all the 
questions you'll find in the 
advanced-class exams. 
The only booto that covers 
transistors and sideband, 
and knowledge of both is 
positively required to pass 
the exam. Thoroughly 
prepares you to answer 
exam questions dealing 
with harmonics, parasitic oscillation* 
oscillators, feedback, and neutralization; 
antennas, transmission lines, and SWR; 
ret&ver circuits; transmitter operation; 
and transmitter circuits and adjustments. 
The final chapter covers measurement of 
frequency, modulation, voltage, resistance, 
etc.— ihings you need to know to operate 
legally and efficiently. 192 pps., 73 iflus. 
Order No, 527 Si, 95 hardbound; S3.9S paper 



GENERAL-CLASS 
LICENSE STUDY GUIDE 

AMATHJRRAOC 



CLASS 

uce*3 

STUDY 



U 



Teaches, in simple 
everyday language, the 
technical aspects of ham 
radio considered 
necessary prerequisites to 
passing the Gen era*- Class 
exam. The author takes a 
patient and personable 
approach, yet gets right to 
the heart of the technical 
questions the FCC will ask 
on the General-Class 
exam. Each question is dealt with in- 
dividually, and the answers are explained in 
depth, bul at a level that can be easily un- 
derstood by relatively Inexperienced, 
nontechnical readers. The text follows the 
philosophy that learning— not mernorlz. 
ing — Is the key to successfully entering the 
higher grades of amateur radio. Pertinent 
facts are grouped Into palatable doses. 
Order No. 551 56,95 hardbound; 55.95 paper 

HAM RADIO INCENTIVE 
LICENSING GUIDE 

gp? Get started in amateur 

radio — or advance to a 
higher class — with the aid 
of Ihis new book. New FCC 
rules now in effect en- 
courage radio amateurs to 
learn more about com 
municattons electronics 
and therefore become 
eligible for higher class 
licenses with special 
'l>fc,Wf3M operating privileges. This 
book contains the information needed to 
pass all the ham license exams — Novice. 
Technician, Conditional, Advanced, and 
Extra Class Included are study sections for 
each class, from learning the code to 
equipment and operating rule 
requirements, Specific question and an- 
swer sections make it useful to ali hams and 
would-be Novices 160 pps. 
Order No. 469 SA.95 hardbound; S3. 95 paper 



ElftttS 

Lbs 

Br 



EXTRA-CLASS 
LICENSE STUDY GUIDE 

Although written as a 
study course for the ham 
radio enthusiast, much of 
the content In this prac- 
tical guide covers material 
jjjj needed to pass the FCC 

fl^. ^f9 Ist-Ciass Radio telephone 
5l|| rL„_ License Exam, Thus, it 

has a great deaf to otter 
anyone desiring to ad- 
vance his knowledge of all 
kinds of radio commun- 
ications systems — modulation, bandwidth 
spurious radiation, sidebands, transmission 
lines, etc, And for the amateur radio 
operator who aspires to become one of the 
elite, this book is a must! In fact, It's fhe 
only book entirely devoted to the subject* 
Begins with AGDC theory and winds up 
with RF power amps, measurements, and 
RTTY. 224 pps,. 162 illus. 
Order No. 543 S7.95 hardbound ; $4.95 paper 

COMMERCIAL FCC 
LICENSE HANDBOOK 

~: A new and unique study 
guide and reference 
manual, combining theory 
and applications with up- 
to-date questions and 
answers for 1st, 2nd, and 
3rd class radiotelephone 
license exams plus 
broadcast and radar en- 
dorsements. Everything 
you need to know is in- 
cluded — complete detailed 
answers to questions on any sub feet you 
may be asked when you take your exam. 
Numerous practical examples are used to 
describe the various principles. In each 
case, the author painstakingly explains the 
answers to questions on all subjects In- 
cluded on the exams. Thus, ihe content not 
only thoroughly prepares you for any exam, 
but also for practical reference. 432 pps. 
Order No. 582 %B.9S hardbound; 15.95 paper 



CIIIEUI1L 

FCC 

LICI1SE 

Mllllll 



OTHER HELPFUL AMATEUR RADIO BOOKS AVAILABLE ON FREE 10 DAY TRIAL 






SOLID STATE PROJECTS 
FOR THE EXPERIMENTER 

A3 projects are of interest 
to hams, ranging from a 
simple transislor tester to 
a capacity meter, from an 
electronic counter to a 
ham TV receiver. Contains 
small construction 
projects the average 
builder can put together — 
projects using readily 
available and inexpensive 
solid state devices which 
give the best results for the least in- 
^tment There are circuits for a noise 
clipper, conveners, preamps. IF strips, 
filters, pulse generators, art IC counter, 
transistor tester, and a completely Iran- 
Ststorized copy of the fabulous Drake 2B 
receiver! Hams and experimenters will 
find audio compressors, transistor power 
omps, exciters tor sideband, etc. 2?4 pps. 
Order No. 591 $6,95 hardbound ; S3, 95 paper 



104 HAM 

RADIO PROJECTS 

Here It a well-rounded 

assortment of devices, 

UAM RAflin m * n * v0u ' 11 w ani to build 

riHiwi rvwiu and use m your snack 

PROJECTS Pdrticular emphasis has 

been placed on Iran- 
—•m , uc^*» - smitting and receiving 

gear, including 
modulators, monitors, 
filters, BFOs, and con- 
verters In addition, there 
are projects for the SO, 40, 
and 15 meter Novice, 6, 2, 1 ' i, 3* meter, and 
1296 MHz for Technician classes. In all the 
10 categories include antenna devices* 
audio equipment, CW aids, interference 
suppressors and eliminators, power sup- 
plies, preamps and preselectors, receivers 
and converters, transmitters, and tran^ 
smitter receiver accessories. A lot of fun for 
Tittle money. 192 pps. 
Order No. 468 SA.95 hardbound i £3.95 paper 



VHFKAMRADI0 

HANDBOOK 



VHF HAM 

RADIO HANDBOOK 

Explains how to make use 
of the many VHF-UHF 
techniques— hints and 
kinks, transmitters, an- 
tennas, equipment 
modifications* receiver 
and modu I a tor c i rcu its. 
etc. The final section 
describes 25 VHF con- 
struction projects, in- 
cluding transmitters, 
receivers, preamps. 
filters* RF amplifiers, a field strength 
meter, noise generator, and a VFO tor all 
bands. Other chapters cover VHF 
propagation phenomena and power supply 
considerations. Written for the ham who 
takes pride in contributing to the ad- 
vancement of the art. Truly a book every 
ham will want to own. 176 pps., over too 
illus. Scores of construction projects. 
Order No. 460 $3,95 paper 



NO RISK COUPON. ..MAIL TODAY! 
TAB BOOKS, Blue Ridge Summit, Pa. 17214 

Please send me the following books on FREE 10-day trial. (Please specify hardbound or paper cover.) 

□ Please invoice on FREE 10-day trial. D Send FREE Catalog, 

D I enclose S □ 573 D 551 D 543 Q 527 D 469 □ 582 □ 591 □ 468 □ 460 



NAME 



ADDRESS 



CITY 



STATE 



ZIP 



SAVE POSTAGE by remitting with order if paying m foreign currency, please add 10'.. Pennsylvania residents must *dd&* tax 



73 32 



122 



73 MAGAZINE 



BONUS SALE! NEW LOW. LOW PRICES ! 

free 810 operational amplifier (dual) DIP w/data for all prepaid orders of $10. or more. 

, , $1 .25 value 

FREE 810 op-amp and one LM309K 5 volt 1 amp, power supply module (TO-3) with 
prepaid orders of $25. or more ..,.,...,,., $3,75 value 

With prepaid orders for $50. or more you get the $25. bonus plus ten per cent discount 
on all items purchased. 




EPOXY TRANSISTORS 

Popular numbers, all factory-marked with 2N-type 
numbers. Guaranteed minimum of 40 pieces of 
TO-5 and TO-18 mixed. Untested, but sampling 
indicates over 85% good. 

approximately 1 -ounce— 40+ transistors 

for only $1 .89 

DIGITAL SPECIAL 

Ten brand new (on carriers) dual-in-line JK flip* 
flops— LU 321 with data sheet and two pages of 
application notes describing hookups for— divide 
by three through ten, and twelve. Also self 
correcting ring counter hookups, etc, 

10 LU321 W/data $5,00 



TTL dual-in-line 
7400, 7401, 7402, 7404, 7405, 7410, 
7420,7430,7440, 
7450, 7451, 7453 . . . .eaX 30 

7441 BCD decoder driver ....*■...„... 1 .40 

7442 BCD decoder . 1.40 

7473 dual JK flip-flop 65 

7474 dual type D FF ,50 

/*r / j Quad latcn -*---**«••.•*•***••#•••* i .*tU 

7476 dual JK FF ....65 

7480 gated full adder [ 80 

7483 4 bit full adder . , 1.60 

7486 quad exclusive or gate ..,......,«.*.* *65 

7489 64 bit RAM 4.00 

7490 decade counter . , . L40 

7491 8 bit shift register . , . . 1.40 

7492 divide by 12 counter . 1 .40 

7493 4 bit binary counter . « 1 .40 

74 1 54 one of 1 6 decoder . . . 3 .00 

74192 up/down decade counter . . , 2,25 

74193 up/down binary counter . 2,00 

74195 unv. 4 bit SR 1.40 

8220 parity gen/checker .1 ,00 

8242 4 bit comparator ,. # *•»••♦■#.. i 90 

8280 preset decade counter 1 .40 

8281 preset binary counter . 1.40 

8520 25 MC divide by "N" 

2 to 15 2.00 

7495 4 bit SHIFT REGISTER 1 .40 

8590 8 bit shift register 2,00 

8270 4 bit shift register 2.00 



LINEAR SPECIAL 

Ten (10) Teledyne TO-5 741 operational amplifiers 
with a two-page sheet of application notes covering 

the basic circuits using op-amps . $.75 each 

Op-amp package 10-741's, data sheet and applica- 
tion notes . . ,.,,.., only $7.00 



DIGITAL COUNTER MODULE 30MC 
unit includes board, SN7490, 
SN7475 quad latch, SN7447 
7 -segment driver and RCA 
"numitron" display tube 
W/deeimal. 1" x 4.5" module 
will mount on 1" centers. 

kit $12 — wired and tested $15 



LED Red Eirjitting Lamp 60 

LINEAR ICs (dual-in-line) 

709 operational amplifier ■ .50 

710 voltage comparator * .75 

LM309K5V-IA 

power supply module 2 JO 

LM 100 positive voltage reg. 80 

747 dual 741 op amp DIP 1.25 

LM302 voltage follower op-amp *.......«♦ 1.25 



All ICs are new and fully tested — leads are plated 
with gold or solder. Orders for $5 or more will be 
shipped prepaid. Add 35rf handling and postage for 
smaller orders. California residents add sales tax. IC 
orders are shipped within two workdays of receipt 
of order — kits are shipped within ten days of 
receipt of order. Money back guarantee on all 
goods sold. 




ELECTRONICS 




SEND FOR FREE FL YER 



•m- 



P.O. Box 85 
CARMICHAEL, CA 95608 

(916)966-2111 






APRIL 1972 



123 



— 



RADIO BOOKSHOP 



FM ANTHOLOGY $4.95 

Reprints from the FM Bulletin (Feb 67-Feb 68) 

including the new regs for 150 MHz marine uvo-way 
communications, mobile noise suppression techniques, 
a direction-fmding antenna for 146.94 MHz, four 
transistor crystal controlled converter for 2m FM t 
three oscillators for tuning up FM receivers, inex- 
pensive preamp for 2m and 6m, design info on 
antenna matching* discussion of repeater proposals 
before the FCC, description and details on Baltimore 
repeater WA3DZD, first five chapters of the infamous 
Chronicles of 76, a simple TVI eliminator, converting 
the GE mobile supply to ac operation, community 
public service, good and bad points of popular surplus 
450 equipment, description of W6FNO repeater, using 
different modes in a repeater control mobile, how 
frequent should a repeater ID be?, using 2m FM 
between planes, multiple repeater power outputs, 
plans and circuit for a hand transceiver, how about a 
cross country 2m FM net?, mobile telephone setup 
using a 450 repeater, description of Buffalo repeater* 
12 foot omnidirectional antenna a la Comprod and 
Prodeiin, plans for encoder and decoder, SAROC 
goings on (ahem!), power amplifier for home builder, 
new telephone regulations for attachments, etc* 

THE BEST OF FM $4.95 

A huge selection of the best technical and con- 
struction articles from the FM Journal including data 
on the formation of a repeater group, licensing a 
repeater, transistor switching for receivers, 450 MHz 
gain antennas, adjusting deviation without test equip- 
ment, narrowband vs wideband, crystal production 
from raw quartz through final inspection, transistors 
over vibrators for mobile, satire on the 41V, eliminat- 
ing tubes in early hybrid uand units, transistor preamp 
for mikes, frequency division and multiplexing in 
repeater control, adjacent repeater problems, multi- 
frequency for the GE S ac supply for the H23 handie- 
talkie, narrowbanding the Pre-Prog 450 units, convert- 
ing 456 Prog Line Telephone mobiles for ham use, 
improving the Gonset FM Communicator, improving 
450 Pre-Prog receivers, Wichita repeater, AREC net 
and public service, quickie T-power and whine filter, 
logic elements for touch tone decoding, FM vs other 
modes, squelch for Motorola Pager, instructions for 
repeater owners, priority inputs for a repeater, four 
freq for Pre-Prog, 6-Freq osc for SOD and 140D, FM 
clinic, FM takes over AM, checking crystal ovens, 
ni-cad charger, mobile hints, and etc. 

ATLAS OF FM REPEATERS $1 .50 

Listing, by state and city, of all repeaters, both 

open and closed, in the world, complete with coverage 
maps of many of the major repeaters. Maps are 
included showing the states and counties, with the 
areas of repeaters indicated. 



REPEATER BULLETIN $2.00 YR 

Monthly bulletin of news and activities of the New 
England Repeater Groups. Lots of opinions, con- 
troversy, reports, even technical articles and think 
pieces. This bulletin is available free to all amateurs 
living in the New England states who are active on 2m 
FM. Outside of this area the subscription price is $2 
per year. Issue number one was January 1 972* 

The Bulletin is the place where the mass of FM 
information is published that doesn*t make it into 73 
because there just isn't enough room. It runs about 24 
pages per month (8H X 11). 

If you are interested in a subscription send your 
name, call, address, including zip, a list of the FM 
equipment you are using, the repeaters you use, and 
any repeater clubs or other amateur radio clubs that 
you are a member of. 

FM REPEATER CIRCUITS MANUAL $4.95 

HADRBOUND EDITION 



This 300-plus page book has material on 
basic FM repeaters, national standards for FM re- 
peaters, carrier operated repeaters, tone decoders for 
repeaters, controlling repeaters with tones* improving 
repeater intelligibility, minimizing desensitization, 
solving inter modulation problems, digital identi- 
fication, the WB6BFM identifier, a computer- 
optimized digital identifier, WA0ZHT design data, the 
Curtis identifier, the K6MVH auto patch, the Zero 
DKU autopatch, the touchtone autopatch, setting up a 
mobile station, encoders for sub-audible, tone burst 
and whistle-on use, multichannel scanning, RF pre- 
amplifiers for repeaters, antennas for 2m FM, collinear 
gain antenna for repeaters, welding rod groundplane, 
high gain mobile antenna, poor man's frequency 
meter, signal generator circuits, RF power measuring, 
adjusting deviation, pocket sized transmitter and 
receiver, low cost portable transmitter for repeater 
use, UHF transmitter, super-regen receiver, repeater 
zero beater, repeater controller, 10-rninute timer, 
repeater audio mixer, and more! 



r 



Mail to 



RADIO BOOKSHOP 

Peterborough NH 034S8 



1 



Name 



Street 



City. 



State« 



Zip 



b 



Call 



Please enclose separate sheet listing books ordered. 




124 



73 MAGAZINE 



Semiconductor Supermart 

• MOTOROLA • RCA • FAIRCHILD • NATIONAL • HEP • SIGNETICS • 



DIGITAL READOUT 





^■r^H 


k 



$340 



Actual Size 



At a price 
everyone 
can afford 

• Operates from 5 VDC 

• Same as TTL and DTL 

• Will last 250,000 hours 



SPECIAL OFFER 

• Digital readout 

• 8CD to 7 — Segment 
Decoder/driver 

• 7490 Decade Counter 

• 7475 Latch 
Only $8.40 



PLESSEY 

SL403D 

3.5 W AUDIO AMP IC 

HI-FI QUALITY 

$3.95 

with 1 2 pages of 
construction data 



The MiNitron readout is a miniature direct 
viewed incandescent filament display in a 16 -pin 
DIP with a sealed front lens. Size and appearance 
is similar to LED readouts. The big difference is 
the price. 



MC1550 

C A 3020 

CA3020A 

CA3028A 

CA3001 

MC1306P 

MC1350P 

MC1357P 

MC1496 
MFC9020 

MFC4010 
MFC8040 
MC 1 303P 
MC 1 304P 



• > 



POPULAR IC's 
Motorola RF amp . . 
RCA % W audio . , . 

RCA 1 audio 

RCA RF amp 

RCA 

Motorola % W audio 

High gain RF amp/I F amp . . 

FM IF amp Quadrature det . 

Hard to find Bal. Mod 

Motorola 2-Watt audio 

Multi-purpose wide band amp 

Low noise preamp 

Dual Stereo preamp ....... 

FM multiplexer stereo demod 



$1.80 
$3.07 
$3.92 
$1.77 
$6.66 
$1.10 
$1.15 
$2,25 
$3.25 
$2.50 
$1.25 
$1.50 
$2.75 
$4.95 



NATIONAL DEVICES 

LM370 AGC/Squelch amp $4.85 

LM373 AM/FM/SSB strip $4.85 

LM309K 5V, 1 A regulator. 3-lead TO-3 case. 
Easy to use. Recommended for all TTL circuits 
$3.50 



MPF102 JFET $.60 

MPF105/2N5459 JFET $.96 

MPF107/2N5486 JFET VHF/UHF $1.26 



MPF121 
MFE3007 
40673 
3N140 

3N141 



Low-cost dual gate VHF RF . . $.85 

Dual-gate $1 .98 

$1.75 

Dual-gate $1.95 

Dual-gate $1.85 



. 



PLESSEY INTEGRATED CIRCUITS 
GREAT FOR SSB RCVRS AND XMTRS 
SL610 low noise 150 MHz RF good AGC 

$5.65 

low distortion IF good AGC 

AGC generator for SSB rcvrs 

AGC gen. SL630 Audio 

multipurpose audio amp 

top performing balanced mixer $10.88 

low noise rcvr mixer $10.88 



* » 



* * . - 



PREMIUM QUALITY 

TEXAS INSTRUMENTS 

TTL IC'S 

7447 Decoder/driver for the digital 
other 7-segment displays 

7400 gates 

7441 NIXIE driver 

7490 decade counter 
7475 quad latch .... 

7495 shift Reg 

7493 divide by 16 . . 
74121 monostable . . 
7473 dual flip-flop . . 



readout or 
$2.25 
.$.35 
$1.95 
$1.40 
$1.40 
$2.00 
$1.90 
$1.80 
. $.85 



MOTOROLA DIGITAL 
Quad 2-input RTL Gate 

Dual Buffer RTL 

Hex Inverter RTL 

Dual J-K Flip-flop 

Dual Buffer RTL 

MC1013P85 MHz Flip-flop MECL 
MC1027P 120 MHz Flip-flop MECL 

MC1023 MECL Clock driver 

MC4024 Dual VCO 

MC4044 Freq. Phase Det 



MC724 

MC788P 

MC789P 

MC790P 
MC799P 



.$1.00 
.$1.00 
.$1.00 
.$2.00 
.$1.00 
. $3.25 
. $4.50 
. $2.50 
. $3.00 
. $3.00 



TRANSISTORS & DIODES 
MPS6571 $.60 



SL612 
SL621 
SL620 
SL630 
SL640 
SL641 



mm* 



» • * 



S5.65 
$8.30 
$8.30 

S5.35 



SIGNETICS PHASE LOCK LOOP 

IME561B Phase Lock Loop . 

Phase Lock Loop 

Phase Lock Loop 

VCO (Function Generator) 
Tone Decoder (PLL) 



NE562B 
NE565B 
NE566V 
NE567V 



$9.50 
$9.50 
$9.50 
$9.50 
$9.50 



* * • 



... *J \J 

$1.00 
$1.00 
$1.00 
$1.00 
$1.00 



MPSA12 NPN Darlington gain 20K 

2N706 packet of 4 . . 

2N2218 packet of 2 . . 

1N4001 packet of 6 . . 

1N4002 packet of 6 . . 

IN 4004 packet of 6 . . 

Please add 354 for shipping 

Circuit Specialists 

Box 3047, Scottsdale, AZ 85257 

FACTORY AUTHORIZED DISTRIBUTOR FOR 

Motorola HEP - Circuit-Stick — Plessey 
All devices are first quality and are 
fully guaranteed. 






APRIL 1972 



125 



ONLY MOTOROLA SELLS MORE 

TWO-WAY EQUIPMENT 

THAN SPECTRONICS 

Our's of course are for amateur use only! 



\ 










T 




i, A *»« »***«"•* 













f 






Don't miss our monthly specials for Motorola 
Equipment on the back covers of RPT Magazine 



1009 



SPECTRONICS, INC 

THE FM PEOPLE 
Garfield St., Oak Park, 
Phone: (312) 848-6778 




60304 



126 



73 MAGAZINE 



Buy Anv 3 

Take 10** 

Discount! 



GIANT SALE ON NEW TTL 
TEXAS & NATIONAL ICs 



lOO or more, 25 fw discount 
Factory Guar,tnt»*d! Tatted! Marl 



Typ* 

SN7400N 
]SK7401N 
D SN7402N 
Q SN7404N 
Q SN740SN 
QSN7410N 
SN7420N 
JSN7430N 

SN7440N 

J SN 7 44 IN 

D SN7442N 

D SN7446N 

DSN7447N 

□ SN7448N 
D SN7472N 
D SN7473N 
D SN7474N 
D SN7476K 
fl SN7481N 
H SN74S3N 
G SN7490N 

! SN7491N 

D SN7492N 

D SN7493N 

Q SN7494N 

DSN7495N 

] SN7496N 

] SN7412I 
D SN74123 
DSN741S1 

I SN74162 

□ SN74192 
Q SN74193 



Circuit Functions 
Quad 2 input gate .....*•*., 

A SN740ON, with open collector 
Quad 2 input NOR Rate . ...... 

Hex mverier .............. 

Hex Invertert open collector , , 
Triple 3 input HAND gate , . , , 

Ouat 4 Input NAND gate 

8 input NAND gate . » . 

Dual 4 input NAND buffer .... 
BCD -to -dec I ma I decoder/driver 

BCD-to-declmal decoder 

BCD -to '7 -segment decoder/driver 
BCD -to -7 -segment decoder /driver 
BCD-to-7 -segment decoder /driver 

J-K Master slave Hip flop 

Dual J-K Master slave flip flop , . 
Dual D triggered flip flop , , 

5N7473N. with preset & clear 
16 Bit scratch pad MEMORY 
4 Bit binary FULL ADDER . . . 
Decade counter ............ 

6 Bit shift register . . . . 

Divide by 12 counter ,<*...- 

4 Bit binary counter 

4 Bit shift register 

4 Bit right shift left shift reg. . 

5 Bit shift register ........... 

One short multivibrator 

Dual retrig l-s/multiv, with clear 

4 Bit arithmetic logic . 

Look ahead carry generator 

Up /down decode counter ...... 

Up /down binary counter . 




BRAND NEW! LINEAR IC AMPS 

Factory Guaranteed! Factory Marked! Factory Tested 

Tvpe Description 

DSN5510L 40MZ. Video Amp 
□ 702 Hi Gain, DC amp TO 5 

703 RF-IF, 14 hookups, TO-5 
D 709C Operational Amp*** . . . 
710C Differential Amp*** 
| 7 11C Memory* Sense, Amp*** 

723A Vottage Regulator *** 
| TVR 2000 Hi-powef 723 +** 
! 741C Freq. Comp. 709*** . . . 
| 748C Freq. Adjustable 741*** 
D 709-709 Dual 709'* (DIP) . 





n 741-741 

□ 739-739 

□ 749-749 



Dual 741's (DIP) , . 
16 Transistor stereo 
PREAMP (DIP) 
Dual channel audio 
amp (DIP) . . . T , 4 



SfiJe Salt- 


S3.SO 


3 for 9.0U 


.79 


3 for 2.00 


1.19 


3 for 3.00 


. .59 


2 for 1.00 


, .S9 


2 tor 1.00 


■ ■ w' 5r 


2 for 1.00 


. 1.49 


3 for 3.7 5 


1.59 


3 for 3.95 


. 35 


3 for 2.50 


. .95 


3 for 2.50 


1.49 


3 for 4.00 


. 2.25 


3 for 6.00 


. 2.49 


3 for G.OO 



2.49 3 

<\ t \\v l>t, 2n\i rhiilcf. |>u.il In Line. 



for 6.00 

TO-ri. 



INTEGRATED CIRCUIT SOCKETS 



Buy Any 3 
Take I0 & o 
Discount! 



Z2 14-Pin, dual in line 
16*Pin, dual in line 
D TO-S, 8 or 10 pins 



NATIONAL LM-565 
PHASE LOCK LOOP ICs 

C Dull In Lie* G TO-S Caw 





6 


AMP FULL 


WAVE 


BRIDGES 


M 7***^ 






nu 


S.1 


AX 


D 


400 


150 


Wfr^^ 




D 


50 


% 


68 


a 


600 


1.75 


W^T^ 


^ 


□ 


1O0 


i 


99 


a 


BOO 


1.95 


^^^-^ 


**. 


□ 


2 DO 


1 


25 


a 


1O00 


2.25 



"AMATEUR" 400 MC NPN 
HI POWER TRANSISTOR 

a Only $2.95 Bu * 3 — Take lOV. 

TOGO case. Similar to 2N3632 . 400 mc, 
3 amps, 60 bvebo. 100 hfe 2 3 watts* 





'SILICON' TUBES 



D5U4 

DSR4 
] 866 



.31.49 
. 3.95 
. 7.95 




INCANDESCENT 

ALPHA-NU MERIC 
7-SEGMENT' 
READOUTS L 



3.95 




Buy any 3 Take 10 7* Discount 

A Poly Pak exclusive! Two different types. Both 
compatfble with SN7446 t 5N7447. SN7448, 
SN747S, 5N7490 and SN741S2 IC*t. Both with 
decimals, O to 9 numerals and 10 letters. With 
specs aV hookups. 

D 16-PIN MICRO MINIATURE 

Fits Into 16 pin dual in line socket. Life: 250,000 
hours. Delivers 700- ft. Lamberts brlteness with 
5 volts 8 mils per segment. Characters .362" H. x 
.197'' W 



1 1 



□ 9-PIN TUBE TYPE 



For printed circuit board or socket. Life: 100,000 
hours. Delivers 6,000*ft. Lamberts with 5 volts 
23 mils per segment. Characters .47" H. x .26" W. 



7-SEGMENT □ 

ALPHA-NUMERIC $6.50 
LED READOUT 




for % IS 



0-9numtn?rs and 9 letters. Compatible withSN7446 
and SN7447 7 -segment BCD IC drivers. Snaps into 
dual in line sockets. Only */+ x l / 4 * ■/■ "- SpeCssSV 
20- mils. 



■ ^ 



i. 




D 



ilRCHILD "VISIBLE" LEDs 

Buy 3 — Take 10% Discount! 



— ^ Color: Red. For readouts, panel 
*™C lights, etc, TO- 18 case. 



3.88 




WESTIHGMOUSE 

3 tor $10 



SOLID STATE 
AM-FW TUNER 

FM 88-108mhz & AM 53 0- 
1 GOOkes. Sensitive 2 3 .. a x 2 V 4 
x lVa w module. Can be used 
with 10.7 me & 455kC* IF 
strips & any hi-fi amp, P.(.\. 
wired. 4 "gang variable »un- 
pty voltage 9V 6 mils, Varac- 
lor diode fur AFC, Schematics. 




ALLEN BRADLEY'S 
'TRANSISTOR' POTS 

Type F. Screwdriver adjust. 

Ohms 
DIM D SOO D2.SK Q20K QlOOK Q SOOK 

] 2O0 i.OK US. OK J 25K 200K Q 1 Meg. 
D25OQ2,0KDi0K Q SOK D^SOK D 2 Meg. 

'MICRO-POTS' 
2 for $1 

Ohms 

Q100 Dl.OK 

2S0 D2.5K 

SOO ;j5-0K 




Tvpe <i< 1/2" diii. s 
i 2" high, M minis 1 I" 
hole, with Shaft, linear, 
immersion- proof high 
freij. 

D 10K Q lOOK Z 1 Meg. 
] 25K I 2SOK 2 Meg. 

3 SOK SOOK 5 Meg. 




EPOXY SILICON 


HIGH yflLT' If 


RECTIFIERS *micromini 


PIV 1 AMP SALE 


p|V 2Amp* 2Amp 3Amp 






2000* 1-00 


50 SOS $.05 s.oa 






3000 1.35 


100 .06 .06 .12 






4000 1.65 


200 ,07 .07 .15 






5000 2.25 


400 .09 .09 .22 






6000 2.96 


SOO 12 .12 .28 
SOO .15 .15 .39 


1 


8000 3.50 


IOOO .IB .18 .45 


r~ 


10000 3.95 



COUNTING 
SYSTEM 



hiWudAa sn'7 490, dec- 
ade counter. SN7 4T5 
latch, SN7441 BCD de- 
coder driver* 0-to-9 
Nixie tube, socket & 
instructions. 



5-Pc. Kit 

6.99 





□ 15* CATALOG on Fiber Optics, MCs r , Semrs, Parts 



Term*: add postage, cod's 25 %. Rated: net 30 
Phone Orders: Wakefield, Mass. (617) 245-3829 
Retail; 211 Albion St.. Wakefield, Mass. 
C.O.D/S MAY BK PHONED IN 

P.O.BOX 942A/*LYNNFIELD, MASS. 01940 



APRIL 1972 



127 




— 



READER SERVICE 

Please either tear out this list of advertisers and send 
It in to 73 with as many boxes checked off as you 
would like to see brochures, data sheets or catalogs , . . 
or eUe make a copy and send that in. Do NOT fail to 
send for data on those products and services that 
interest you. Your magazine will be as large as the 
number of ads allow it to be . . . so the more you 
encourage the advertisers the bigger magazine you will 
have. When you send for information, the advertisers get 
encouraged. Send. 



ADVERTISER INDEX 



April, 1972 



D Amat. Whol. Elec. 113, 1 

D Antek 103 

D ATV* 115 

D Avanti 74 

a A^com 69 

i i Babylon 123 

D B& W 103 

□ Callbook 116 

D Camp Bulter 102 

C Circuit Specialists 125 

n Clegg 61 

n Comcraft 94 

u Commun, Spec. 84 

U Cornell 114 

D Data Eng. 41, 115 

a Dayton Hamvention 113 

D Digital Inst, 119 

Digitone 113 
D Drake 54 
D E astro n 113 
D Epsilon 119 
D Erickson 82 
D E.S. Enterprises 50 
G Fair Radio 1 14 

□ Fiam 100 

D FM Ham 115 
D Frank 1 15 
D Freck 66, 67 
D Sid Glass 80 
p Goodheart 116 

□ Gregory 78 
D Hal 116 

□ Hamtronics 70, 71 
D H& L 114 

u Henry 30, 58, 59 

□ Jan Crystals 101 
D Janel 113 

D Jefftronics 103 
D Jensen 115 
D Juge 62,63 
D Kass 100 



16 □ Kirk 102 

□ K&W find. 92 

□ Lee 114 

D Linear Systems 77 

P Mann 85 

a Micro-Comm. 96 

a Mini-Products 40 

D Mtn, West Alarm 119 

D Newtronics 89 

D IMu Sigma Alpha 115 

□ Palomar 80 
D Payne 103 

D Pearce Simpson 83 
D Poly Paks 127 
a Rim Systems 119 

□ Robot Cover IV 
D Ross& White 75 
D RP* 101 

D R & R 120, 121 
D Savoy Cover III 

□ Sentry 98 
D Slep 106 

□ Sonar 65 

D Spectronics 126 
D Standard 57 
D Tab 122 

□ Telecom 79 

□ Tel rex 24 

u Unimetrics 88 

□ VAN W2DLT 115 

□ Vanguard 91 

□ VHF Specialists 80 

□ Vibroplex 113 
D Wolf 119 

O World QSL 113 
73 Stuff 

Subscriptions 90, 91 

73 European Tour Cover II 

FM Books 50 

Radio Bookshop 124 



^Reader Service inquiries not solicited. Correspond di- 
reactly to company. 



Mail to: 73 INC., PETERBOROUGH NH 03458 

PLEASE PRINT OR TYPE 



Name 



Call 



Address 



Zip 



128 



PROPAGATION CHART 
J, H. Nelson 
Good (Open), Fair (Q), Poor (O) 



April 1972 



SUN MON TUES WED THUR 



FRI 



SAT 













1U 






2 


3 4 . 


5 


6 7 8 












9 10 ( 


u 


)t 


\A 


13 14 15 


16 (JL7) IE 


\\ 


d 


20 21 22 












2J 




f *^V J"" ***v ^"^^""v 


, 


25 24 | 


26| 


(27) (28) (29) 




( 


22 


) 








V^*/ X^^/ V^^ 






EASTERN UNITED STATES TO: | 






GMT: II It M og a 


10 12 14 16 1ft 20 22 






ALASKA 


M 


14 


7 


7 


7 


7 


7 


7 


7 


7A 


14 


14 






ARGENTINA 


21 


14 


14 


7A 


7 


7 


14 


71 


71 


71 


21A 


71 






AUSTRALIA 


31 


14 


™ 


7B 


7B 


7 


7 


14 


14 


71 


14A 


14A 






CANAL ZONE 


71 


14 


»*, 


7 


7 


7 


14 


21 


11 


11 


11 


21 




ENGLAND 


7 


2 


7 


1 


7 


I» 


14 


14 


14A 


14 


U 


14 






HAWAII 


14A 


14 


76 


7 


7 


7 


7 


78 


14 


14 


14 A 


MA 






INDIA 


7 


7B 


76 


78 


76 


7B 


14 


14 


14 


14 


14 


7 




i 


JAPAN 


14 


14 


76 


7B 


7B 


7 


7 


7 


7 


7 


7B 


14 




MEXICO 


14A 


14 


7 


7 


7 


7 


7A 


14 


14 


14 


21 


21 




PHILIPPINES 


14 


7A 


7B 


76 


7B 


7B 


78 


7 


- 

7 


1 — ■ ' — 1 
7A 


UB 


14 




PUERTO nico 


14 


74 


_. 7 


I 


T 


7 


14 


14 


r 14_ _ 


UlA_ 


14 


14 




SOUTH AFRICA 


14 


7A 


7 


7 


7B 


14 


21 


21 


21 


21 


21 


14 




Lf. S. S. R. 


7 

" 


7 


7 


7 


7 


76 


14 


14 


14 


14 


14 


7B 




WEST COAST 


14A 


14 


7 


J 


7 


7 


7 


14 


14 


14 


14 


14A 




CENTRAL UNITE! 


D STATES TO: 






ALASKA 


14 


14 


14 


7 


7 


7 


7 


7 


7A 


14 


14 


14 






ARGENTINA 


21 


14 


14 


7A 


7 


7 


14 

7 


21 


71 


21 


21A 


21 






AUSTRALIA 


21 


71 


14 


78 


7B 


7 


14 


14 


7B 


14A 


21 




CANAL ZONE 


21 


14 


14 


7 


7 


7 


14 


14A 


21 


21 2T 21 




ENGLAND 


7 


7 


7 


7 


7 


7 


7B 


7B 


: 14 


14 


14 


14 




HAWAII 


21 


^4A 


14 


7B 


7 


7 


7 


7 


14 


14 


21 


21 






INDIA 


14 


14 


7B 


7B 


7B 


7B 


7B 


TB 


7 


14 


■< 


14 






JAPAN 


14 


14 


14 


78 


7B 


7 


7 


7 


7 


7 


14 


14 






MEXICO 


14 


7A 


7 


7 


7 


7 


7 


7A 


14 


14 


14 


14 






PHILIPPINES 


N 


14 


7A 


7B 


7B 


78 


7 


7 


7 


7A 146 


14 




PUERTO RICO 


21 


14 


74 


7 


7 


7 


14 


14 


I4A 


21 


21 


31 




SOUTH AFRICA 


14 


7A 


7 


7 


78 


76 


14 


14 


14 


14A 


14A 


14 






U.S.5.R. 


T 


7 


7 


7 


7 


78 


TB 14 


14 


14 


14 


7B 






WESTERN UNITE! 


J STATES TO: 




ALASKA 


14 


14 


14 


7 


7 


7 


7 


7 


, 


7A 


14 


14 




ARGENTINA 


21 


21 


14 


7A 


7 


7 


7B 


14 


21 


21 


21A 


21 






AUSTRALIA 


21A 


21A 


21 


14 


14 


14 


7 


7 


7A 


7B 


14A 


21 






CANAL ZONE 


21 


14 


14 


7 


7 


7 


7 


14 


14 


31 


71 


21 






ENGLAND 


?B 


7 


7 


7 


7 


7 


7 


70 


7B 


14 


14 


14 




HAWAII 


21 


21 


21 


14 


14 


14 


7 


7 


14 


21 


21 


21 




INDIA 


1A 


14 


14 


78 


7H 


7B 


7B 


76 


7 


7 


14 


14 






JAPAN 


14 


14 


14 


7A 


7B 


7 


7 


7 


7 


* 


14 


14 






MEXICO 


21 


14 


7fi 


7 


7 


7 


7 


14 


14 


14 


14 


14A 






PHILIPPINES 


14 


14 


14 


7A 


7B 


7B 


7B 


7 


7 


7A 


14 


14 






PUERTO RICO 


21 


14 


7* 


7 


7 


7 


7 


14 


14 


14 


21 


21 




SOUTH AFRICA 


14 


7B 


7 


7 


79 


76 


78 


74 


14 


14 


14 


14 




U S.5.R. 


7 


7 


7 


7 


7 


78 


7B 


7B 


14 


14 


74 


78 






EAST COAST 


14A 


14 


7 


7 


1 


7 


7 


14 


'* 


14 


14 


14A 





A = Next higher frequency may be useful also* 
B = Difficult circuit this period. 

73 MAGAZINE 






w 



For over 30 years 




TYPE 900 A 



TYPE 901 



Either Type 



RECEIVER — $3.95 



TRANSMITTER — $4.95 



Post paid in U.S. 



Specify crystal type, make and model of 
set, and desired frequency. 



For amateur FM, fixed, 
mobile, and repeater use 
on 144 Mhz band. 



Regency, Varitronics, 
Standard, Drake, Gladding, 
Tempo. Swan, and most 
others. 






lecfc ronicsjnc. 

P.O. Box 7127- Fort Lauderdale. Florida -33304 
Tel: 306-666-8416 or 306-947-1191 



ii 






What 



• t 



you think of SSTV?" 




Doc" Taylor, WQFEE answers 



We recently called Doc, one of the most active 
amateur radio operators in the country, who 
we knew owned a Robot SSTV Camera and 
Monitor, and asked him, "What do you think 
of SSTV?" Here are some of his comments: 
"I've been an active ham since 1946 and SSTV 
is the greatest thing that's ever happened to 
amateur radio, . , I love the friendliness of SSTV 
because we can be so personal, sending pictures 
of ourselves and our families to one another, . . 
I spend practically all my spare time operating 
SSTV. , . there are many, many people on SSTV 
now, new Robot stations are popping up every 
day.,,rve worked Australia, New Zealand* 
Laos, South America, Africa, Italy, Hawaii, 
Alaska. Establishing contacts is no problem,.. 
As far as the Robot equipment is concerned, 



it's excellent equipment, the Cadillac of the in- 
dustry. And IVe gotten excellent service. I'm 
really pleased with the Robot gear." 

ROBOT MODEL 70 SSTV MONITOR ..$495 
ROBOT MODEL 80 SSTV CAMERA. .$465 

For complete information on Slow Scan TV, 
the Robot SSTV Camera and Monitor, and a 
copy of our SSTV operator directory, write: 

1 robot] 

ROBOT RESEARCH INC. 

7591 CONVOY COURT, SAN DIEGO, CA 92111 

(714) 279*9430 



See the complete line of Robot SSTV equipment at your nearest dealer. 

Birmingham, Ala. 35233, James W. Clary Company, 1713 Second Avenue South, (205) 322-2486 • Anaheim, Calif. 
92804 Henry Radio Company, 931 North Euclid, (714} 772-9200 • Los Angeles, Calif. 90064, Henry Radio Com- 
pany, 11240 West Olympic Boulevard, (213) 272-0861 * Oakland, Calif, 94607, Amrad Supply, 1025 Harrison 
Street, (415) 451-7755 • Denver, Colo, 80202, CW Electronic Systems, 1401 B/ake Street, (303) 244-5523 • 
Miami, Fla. 33137, Amateur Radio Center, Inc., 2805 NE Second Avenue, (305) 374-4101 • Honolulu, Hawaii 
96803, Honolulu Electronics, 819 Keeaumoku Street, (808) 949-5564 • Baltimore, Md. 21211 t Amateur Radio 
Center, 1117-19 W. 36th Street, (301) 889-5214 ■ Wheaton, Md. 20902, Electronics International Service Corp., 
11305 Elkin Street, (301) 946-1088 • Reading, Mass. 01867, Graham Radio Company, 505 Main Street, (617) 
944-4000 • Muskegon, Mich* 49441, Electronic Distributors, Inc., 1960 Peck Street, (616) 726-3196 • Butler, Mo., 
Henry Radio (816) 679-3127 • St. Louis, Mo. 63132, Ham Radio Center, 8342 Olive Boulevard, (314) 993-6060 

• Las Cruces, New Mexico 88001, Mannies Electronic and Photo Supplies, 802 So. Solano, (505) 524-3646 • 
New York, N.Y. 10012, Barry Electronics, 512 Broadway, (212) 925-7000 • Ashville, North Carolina 28801, 
Freck Radio Supply, 38 Biltmore Avenue, (704) 254*9551 • Cincinnati, Ohio 45231, Queen City Electronics, 
1583 McMakin Ave., (513) 931-1577 • Cleveland, Ohio 44112, Amateur Electronic Supply, 17929 Euclid Ave., 
(216) 486-7330 • Dayton, Ohio 45404, SREPCO, 314 Leo St., (513) 224-0671 • Portland, Oregon 97205, Port- 
land Radio Supply, 1234 S, W. Stark St, (503) 228-8647 • Pittsburgh, Pa. 15222, Cameradto Co., 2801 Liberty 
Ave., (412) 391-7400 * Trevose, Pa. 19047, Hamtronics, 4033 Brownsville Rd., (215) 357-1400 • Fort Worth, 
Texas 76110, Ed Juge Electronics, 3850 So. Freeway, (817) 926-5221 * Houston, Texas 77002, Madison Elec- 
tronics Supply, 1508 Mc Kinney Ave., (713) 224-2668 • Spokane, Wash. 99206, HCJ Electronics, E. 8214 
Sprague, (509) 924-2343 • Milwaukee, Wise. 53216, Amateur Electronic Supply, 4828 W. Fond du Lac Ave- 
nue, (414) 442-4200 • CANADA; Fredericton, N.B M Audio Lectronics Ltd., 79 Prospect Street, (506) 454-3380 

• Toronto, Ontario, VE Amateur Radio, 3768 Bathurst Street, (Downsview), (416) 636-3636 * Montreal, Quebec, 
Payette Radio Company, 730 St. Jacques, (514) 866-6681.